Reconstruction of the Point-Spread Function of the Human Eye Using a New Phase-Retrieval Algorithm

The double-pass method is thought to obtain the point spread function (PSF) in human eyes based on two techniques: the symmetric double-pass method using the same pupil size and the asymmetric double-pass method using a different pupil size. The symmetric double-pass method provides autocorrelation of the retinal PSF and, thus, the modulation transfer function. The asymmetric double-pass method provides low-frequency partial-phase information and the partial phase-retrieval algorithm is applied to obtain the complete-phase information, and to estimate the PSF. The partial phase-retrieval algorithm is based on the iteration method proposed by Fineup and Kowalczyk and requires a lengthy computation. In this study, we propose a new high-speed phase-retrieval algorithm based on the property that the real and imaginary parts of optical transfer functions (OTFs) continuously change in value.     

A new route for the construction of the AB-ring core of Taxol

A new method for the construction of the AB-ring core of Taxol was developed utilizing a new skeletal transformation protocol as a pivotal step. The acid-catalyzed rearrangement of the cyclopentenone-allene photoadduct gave a bridged seven-membered ketone, which was easily transformed, using the intramolecular Suzuki reaction and the oxidative cleavage of the vicinal diol, to the bicyclic diketone.     

Sonochemistry and its dosimetry

The effects of ultrasound originate primarily in acoustic cavitation. The cavitation bubbles collapse violently enough to lead to interesting chemical effects, known as sonochemistry. There is a great need to relate the efficiency of sonochemical reaction to the energy of ultrasonic irradiation used to produce them. In this paper, three OH radical dosimeters, Fricke dosimeter, terephthalate dosimeter, and iodide dosimeter, are compared from the analytical point of view. The dosimeters based on photometry, i.e., Fricke and iodide, produced reliable and reproducible results, but the sensitivity is not enough for special applications, such as chemical monitoring of single bubble cavitation. The dosimeter based on fluorometry, terephthalate dosimeter, offered high sensitivity, 1.2×10¹¹ molecules ml⁻¹. The effects of some experimental parameters in sonochemistry, i.e., solution temperature and the dissolved gas species, were evaluated with the dosimeters.     

One-step synthesis of 4-aminodihydrobenzofurans and 4-hydroxyindoles via dehydrogenation-heteromercuration of 2-alyl-3-aminocyclohexenones using mercury(II) acetate

On treatment of the 2-allyl-3-aminocyclohexenones with mercury(II) acetate, either sequence, dehydrogenation—oxymercuration or dehydrogenation—aminomercuration, occurred depending on the nature of the amino group in the substrate to yield the dihydrobenzofurans or indoles, respectively.     

Highly sensitive determination of haloperidol in human serum by capillary gas chromatography using a surface ionization detector

A method has been developed for highly sensitive determination of haloperidol in human serum involving a simple extraction procedure followed by gas chromatographic separation. Target components were separated from the extracting solvents with a Van den Berg type solventless sample injector before introduction Into a DB-1 capillary separation column. A surface ionization detector (SID), which has highly selective sensitivity for Substituted amines, was employed for quantitation using bromperidol as an internal standard. Chloroform proved to be the best extracting solvent, yielding a quantitative detection limit of 5 ng/ml (S/N = 2). Comparison of the response to target compounds obtained by the SID, FTD (flame thermionic detector), and FID (flame ionization detector) showed the SID to be superior.     

Classical trajectory calculations of intramolecular vibrational energy redistribution. I. Methanol-water complex

Intramolecular vibrational energy redistributions of the O-H stretching (nuOH) vibration for the methanol monomer and its water complex, the methanol-water dimer, are investigated by using ab initio full-dimensional classical trajectory calculations. For the methanol monomer, in the high-energy regime of the 5nuOH overtone, the time dependence of the normal-mode energies indicates that energy flowed from the initial excited O-H stretching mode to the C-H stretching mode. This result confirms the experimental observation of energy redistribution between the O-H and C-H stretching vibrations [L. Lubich et al., Faraday Discuss. 102, 167 (1995)]. Furthermore, a lot of dynamical information in the time domain is contained in the power spectra, whose density is given by the Fourier transformation of the total momentum obtained from trajectory calculations. For the methanol-water hydrogen-bonded complex, at the high-energy level of the 5nuOH overtone, the calculated power spectrum shows considerable splitting and broadening, indicating significant energy redistribution through strong coupling between the O-H stretching vibration and other vibrations. It is thus clear that the A-H...B hydrogen-bond formation facilitates energy redistribution subsequent to the vibrational excitation of the hydrogen-bonded A-H stretching mode.     

Development of direct fluorination technology for application to materials for lithium battery

Direct fluorination of 1,3-dioxolan-2-one with elemental fluorine was successfully carried out to provide 4-fluoro-1,3-dioxolan-2-one, which was expected as an additive for lithium ion secondary battery. 4-Fluoro-1,3-dioxolan-2-one was also further fluorinated with elemental fluorine to give three isomers of difluoro derivatives by the same methodology. Another topic is the preparation of trifluoromethanesulfonyl fluoride, an intermediate of lithium battery electrolyte, by the reaction of methanesulfonyl fluoride with elemental fluorine. The use of perfluoro-2-methylpentane as a solvent gave satisfactory selectivity of trifluoromethanesulfonyl fluoride.     

Syntheses and electrical conductivity of polyamides containing tetrathiafulvalene moieties in the main chain

Novel polyamides that contain tetrathiafulvalene (TTF) moieties were synthesized by direct polycondensation of Δ^2,2′ -bi-1,3-dithiole-4,4′(5′)-dicarboxylic acid with aromatic diamines in the presence of triphenylphosphine, hexachloroethane, and pyridine. Complexes of these polyamides with bromine were TTF cation radical () salts which resulted from the charge transfer of TTF moieties to bromine. The electrical conductivity of undoped polyamides increased with a decrease in diamine length. By doping the bromine the conductivity of the polyamides was enhanced by 3–5 orders of magnitude and reached 10^?5–;10^?9S cm^?1. Maximum conductivity was observed at the doping ratio of [Br]/[repeat unit] < 1. The electrical conduction in the bromine complexes may be attributed to the hopping of odd electrons of between TTF moieties.     

Direct Visualization of Electromagnetic Microfields by Superposition of Two Kinds of Electron Holograms

A new electron holographic method is presented to directly visualize pure phase objects such as electromagnetic microfields, which is achieved by superposition of two kinds of electron holograms. The method is very simple and is twice as sensitive as the conventional double-exposure electron holography and the four-electron-wave interference. Using this technique, an electric field around a charged latex sphere and a magnetic field around a barium ferrite particle have been directly observed.