著者

山本 達也 Tatsuya YAMAMOTO

雑誌

清泉女子大学紀要 = Bulletin of Seisen University (ISSN:05824435)

巻号頁・発行日

pp.71-92,

著者

山本 達也 岡本 岳大 Tatsuya Yamamoto Takehiro Okamoto

雑誌

清泉女子大学紀要 = Bulletin of Seisen University (ISSN:05824435)

巻号頁・発行日

pp.121-140,

著者

Tatsuya Yamamoto Shoji Shinamura Eigo Miyazaki Kazuo Takimiya

出版者

(社)日本化学会

雑誌

Bulletin of the Chemical Society of Japan (ISSN:00092673)

巻号頁・発行日

vol.83, no.2, pp.120-130, 2010-02-15 (Released:2010-02-15)

参考文献数

40

被引用文献数

59

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In order to gain an insight into the relationship between the molecular structure and the semiconductor characteristics of highly π-extended heteroarene-based organic semiconductors, three structural isomers of dinaphthothieno[3,2-b]thiophenes with C2h symmetry were investigated. Of these, two isomers, dinaphtho[2,1-b:2′,1′-f ]thieno[3,2-b]thiophene (2) and dinaphtho[1,2-b:1′,2′-f ]thieno[3,2-b]thiophene (3), were newly synthesized, characterized, and utilized as active semiconducting layers in organic field-effect transistors (FETs). Detailed investigation of the physicochemical properties of 2 and 3, together with another isomer, dinaphtho[2,3-b:2′,3′-f ]thieno[3,2-b]thiophene (1), indicated that the electronic structures of the three isomers are fairly different from each other despite having the same molecular formula and the same aromatic constituents. Comparison of the molecular arrangements in the crystals elucidated by X-ray structural analysis implied that the molecular shape and the thus-induced favorable intermolecular interactions play important roles in determining the entire molecular arrangement. The characteristics of 2- and 3-based FETs with maximum field-effect mobilities (μFET s) of 10−3–10−2 cm2 V−1 s−1 were inferior to those of 1-based FETs with μFET s up to 3.0 cm2 V−1 s−1. The inferior characteristics of 2- and 3-based devices were due to film morphology as elucidated by atomic force microscopy (AFM) and supported by theoretical calculations of electronic structure in the solid state. Together, the results indicate that the molecular structure and shape, even for similar heteroarenes with the same molecular formula and symmetry, are important parameters to determine the solid-state properties of organic semiconductors.

著者

Yuki YAMAMOTO Tatsuya YAMAMOTO Natsuki YUTO Thomas B. HILDEBRANDT Imke LUEDERS Gudrun WIBBELT Osamu SHIINA Yasushi MOURI Keisuke SUGIMURA Sayuri SAKAMOTO Saroch KAEWMANEE Kentaro NAGAOKA Gen WATANABE Kazuyoshi TAYA

出版者

日本繁殖生物学会

雑誌

Journal of Reproduction and Development (ISSN:09168818)

巻号頁・発行日

pp.1111070413-1111070413, (Released:2011-11-11)

被引用文献数

2 13

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The objective of the present study was to define the secretion of prolactin (PRL) in pregnant African and Asian elephants. Levels of immunoreactive (ir-) PRL in serum and placental homogenates were measured by a heterologous radioimmunoassay (RIA) based on an ovine and human RIA system, and the localization of immunoreactive (ir-) PRL in the placenta was detected by immunohistochemistry using anti-human PRL. Circulating ir-prolactin clearly showed a biphasic pattern during pregnancy in African and Asian elephants. Serum levels of ir-PRL started to increase from the 4-6th month of gestation and reached the first peak level around the 11-14th month. A second peak of circulating ir-PRL levels was observed around the 18-20th month of gestation followed by an abrupt decline after parturition. In contrast, in a case of abortion of an African elephant, the second peak of ir-PRL was not observed, and the levels remained low for about four months until parturition. The weight of the fetus delivered at the 17th month of gestation was 23.5 kg, which was quite small compared with normal fetuses in previous reports. Ir-PRL was detected in placental homogenates, and immunolocalization was observed in trophoblasts in both the African and Asian elephants, indicating that the placenta is the source of ir-PRL during pregnancy in elephants. The present results clearly demonstrated that circulating ir-PRL shows a biphasic pattern during normal pregnancy and that the placenta appears to be an important source of circulating ir-PRL during pregnancy in both African and Asian elephants.