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The concentration of cytoplasmic free calcium (Ca2+) increases in various stimulated cells in a wave (Ca2+ wave) and in periodic transients (Ca2+ oscillations). These phenomena are explained by inositol 1,4,5-trisphosphate (IP3)-induced Ca2+ release (IICR) and Ca(2+)-induced Ca2+ release (CICR) from separate intracellular stores, but decisive evidence is lacking. A monoclonal antibody to the IP3 receptor inhibited both IICR and CICR upon injection of IP3 and Ca2+ into hamster eggs, respectively. The antibody completely blocked sperm-induced Ca2+ waves and Ca2+ oscillations. The results indicate that Ca2+ release in fertilized hamster eggs is mediated solely by the IP3 receptor, and Ca(2+)-sensitized IICR, but not CICR, generates Ca2+ waves and Ca2+ oscillations.

This lecture is not directly related to our discovery and development of conducting polymers to which the Nobel Prize in Chemistry 2000 was awarded. However, I would like to present my previous work that I had carried out just before we reached the discovery of chemical doping. I hope that this will be of use and deepen your understandings by learning what had happened before and how we reached the idea of chemical doping.

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ABSTRACT:The infrared spectra of poly(acetylene), poly(acetyiene-d2), copoly(acetylene+acetylene-d2), and copoly(acetylene tacetylene-d1 +acetylene-d2) prepared by the Ti(OC4H9)4-Al(C2Hs)3 system over a wide temperature range (ca. -100 to 180°C) are reported. A tentative assignment of the observed spectra is made on the basis of model structures in which infinite planar chains of all trans, all trans-cisoid, and all cistransoid configurations are assumed. The spectral data are best interpreted on the basis of an all cis-transoid (or an all trans-cisoid) structure for the polymers prepared at temperatures lower than -78°C, and an all trans structure for the polymers prepared at temperatures higher than 150°C.Simplified calculations of the C-H and C-D out-of-plane deformation frequencies are made for various model chains. It has been concluded from a comparison of the observed and calculated frequencies that the cis-opening of the triple bond occurs in a polymerization reaction with the Ti(OC4H9)4-Al(CzHs)3 catalyst system at low temperatures.KEY WORDS Infrared SpectrajPoly(acetylene)/Deuterated Acetylene/ Ziegler Catalyst/Configuration/cis-Opening/Factor Group Analysis/ Normal Vibration/ Structure and properties of poly( acetylene) prepared with Ziegler-Natta catalysts have been investigated by several groups. Natta, et a!./ presented evidence from chemical properties and X-ray diffraction data, indicating that the poly-(acetylene) obtained had linear chains of conjugated double bonds of trans configuration along the chains. poly(acetylene) containing a 60-70% cis content obtained by a catalyst system of thermally decomposed iron dimethylglyoximate-2-pyridine and triethylaluminum at 25°C or below.

Helical polyacetylene was synthesized under an asymmetric reaction field consisting of chiral nematic (N*) liquid crystals (LCs). The chiral nematic LC was prepared by adding a chiroptical binaphthol derivative as a chiral dopant to a mixture of two nematic LCs. Acetylene polymerizations were carried out using the catalyst titanium tetra-n-butoxide-triethylaluminum dissolved in the chiral nematic LC solvent. The polyacetylene film was shown by scanning electron microscopy to consist of clockwise or counterclockwise helical structure of fibrils. A Cotton effect was observed in the region of the pi --> pi* transition of the polyacetylene chain in circular dichroism spectra. The high electrical conductivities of approximately 1500 to 1800 siemens per centimeter after iodine doping and the chiral helicity of these films may be exploited in electromagnetic and optical applications.