Polystyrenes with p-oligo-siloxane,silane, germanosiloxane,germane, or stannane as p-substituents as materials for oxygen permeable membranes

The title polymers were synthesized and the oxygen permeation behavior through the polymer films were studied. The oligodimethylsilane-substituted polystyrenes showed a little low Po₂ compared with the oligodimethylsiloxane-substituted polystyrenes. The important role of trimethylsiloxyl group in permeation was suggested.     

Observing quantum tunneling in perturbation series

We apply Borel resummation to the conventional perturbation series of ground state energy in a metastable potential, V(x) = x²/2 − gx⁴/4. We observe numerically that the discontinuity of the Borel transform reproduces the imaginary part of the energy eigenvalue, i.e., the total decay width due to quantum tunneling. The agreement with the exact numerical value is remarkable in the whole tunneling regime 0 < g 0.7.     

Organic dye-doped polymer films for optical phase-conjugate processing

Erythrosin B-doped polyvinyl alcohol (EB/PVA) film, a methyl-orange-doped polyvinyl alcohol (MO/PVA) film and a (EB+MO)/PVA film serve as not only phase conjugators but also hologram-recording media. A phase-conjugate (PC) wave is generated even when a probe wave is linear-polarized orthogonal to the pump polarization direction. Using these dye-doped films, we demonstrate optical PC processing for detecting the phase and amplitude difference between two objects and a moving or time-varying object in a backward degenerate four-wave mixing arrangement.     

Palladium catalyzed oxycarbonylation of 4-penten-1,3-diols: efficient stereoselective synthesis of cis 3-hydroxytetrahydrofuran 2-acetic acid lactones

cis 3-Hydroxytetrahydrofuran acetic acid lactones have been prepared selectively and in high yield by an intramolecular palladium catalyzed oxycarbonylation of 4-penten-1,3-diols under mild conditions (room temperature, 1 atm of CO).     

Spontaneous immobilization of liposomes on electron-beam exposed resist surfaces

We have found an interesting immobilization technique of liposomes on electron-beam exposed resist surfaces. The immobilized liposomes have been visualized by the atomic force microscope and have shown well-organized three-dimensional physical structures, in which the liposomes maintain their shapes and sizes similar to those of the original design in prepared solution. The immobilization is based on a strong static charge interaction between the resist surface and the liposomes. Further experiments show that very strong charge in the surfaces produces the firm immobilization of the liposome. We believe these findings can be related to various liposome applications such as drug delivery system, electrochemical or biosensors, and nanoscale membrane function studies.     

Atomic absorption spectrophotometry of zinc sulfide:Silver phosphors

An AD converter was interfaced between a conventional instrument of atomic absorption and microcomputer. The system can measure signals within a full-scale precision of 0.4%. For a single measurement only a small volume of sample solution, down to 200 μl. is aspirated. Backgrounds and atomic absorption signals are determined after averaging 64 binary data samples from a single measurement. Results of analysis are printed out by computer calculation after the measurements.The system was applied to the analysis of zinc sulfide phosphors having different particle sizes and structures. Differences in the chemical composition were found, for example, the largest size particles had a lower silver content and a higher sodium content than the medium and smaller size particles.     

Concerted interaction between conjugated double bond CHs and multiple OHs in polyene macrolide antibiotic chainin: weak =C-H...O interactions responsible for intrinsic molecular assembly

The concerted interactions observed between five conjugated double bond CHs and four hydroxy Os in the crystal of chainin, a polyene macrolide antibiotic, clarified the existence of unprecedented, weak =C-H...O interactions, which is important for forming its intrinsic molecular assembly.