We prepared a homologous series of liquid crystal trimers in which two cyanobiphenyl units and one octafluorobiphenyl unit were connected via flexible spacers, and investigated their phase transition ...behavior depending on the parity of the methylene spacer. All trimers showed a nematic phase. The trimers possessing odd-numbered spacers were found to exhibit phase separation, i.e., N–Cry and/or Iso–Cry, whereas those possessing even-numbered spacers did not show such an unusual phase coexistence. We discuss the structure–property relationship in the trimers.
We designed an asymmetric dimer possessing a terminal hydroxyl group, and investigated the phase transition behavior using polarized optical microscopy and differential scanning calorimetry. The ...dimer exhibited a nematic phase. On cooling from the nematic phase, two domains with different textures were formed in the crystal. On heating from the crystal, nematic and crystalline phases were found to coexist in a temperature range of 18.2 K. We discuss how intermolecular interactions cause such an unusual phase separation.
A novel isoform of rat estrogen receptor (ER) beta, ERβ2, which is a putative alternative splicing product of the reported ERβ (ERβ1) has been identified. Rat ERβ2 cDNA contains an additional ...in-frame 54 base pair insertion in the ligand binding domain of ERβ1, which generates an 18 amino acid residue insertion. Northern blot and RT-PCR analyses revealed that ERβ2 coexists with ERα and ERβ1 in all tissues examined including brain, lung, liver, kidney, fat, bone, uterus, prostate, and ovary. The insertion caused loss of ligand binding activity of ERβ2, whereas the ability to bind the palindromic estrogen response element (ERE) was retained. In an ERE-containing luciferase reporter gene assay using COS-1 cells, ERβ2 failed to activate estrogen-dependent transcription. Furthermore, ERβ2 dose dependently suppressed the ERα- and ERβ1-mediated transcriptional activation. These results suggest that rat ERβ2 functions as a negative regulator of estrogen action.
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IJS, IMTLJ, KILJ, KISLJ, NUK, SAZU, SBCE, SBJE, UL, UM, UPCLJ, UPUK
We prepared a homologous series of achiral liquid crystal trimers in which two phenylpyrimidine units and one biphenyl unit were connected via flexible spacers, and investigated the phase transition ...behavior and the phase structure using polarized optical microscopy (POM), differentical scanning calorimetry, X-ray diffraction (XRD), and atomic force microscopy (AFM). All the trimers were found to exhibit nematic and dark conglomerate (DC) phases. The AFM measurements reveal that the DC phases have different porous structures depending on the alkyl spacer length.
We prepared an achiral liquid crystal trimer in which two phenylpyrimidine units and a biphenyl unit are connected via flexible heptmethylene spacers, and investigated the phase transition behavior ...using polarized optical microscopy (POM), differentical scanning calorimetry and X-ray diffraction (XRD). The trimer was found to exhibit a nematic phase and a B4 phase composed of chiral domains with opposite handedness. The chiral characteristics of the B4 phase were confirmed by uncrossing the polarizers in opposite directions. XRD measurements reveal that the B4 phase has a monolayer structure. We discuss how the chirality arises in the B4 phase of the trimer.
We prepared an achiral liquid crystal trimer in which three mesogenic units are connected via flexible spaces. We investigated phase transition behavior of a binary mixture of the trimer and 6OCB ...using polarized optical microscopy, differential scanning calorimetry, and X-ray diffraction. A dark conglomerate phase composed of chiral domains with opposite handedness was observed for the binary mixtures containing 55-90 mol% of 6OCB. We discuss how the chirality arises in the binary mixtures.
