Boson peak dynamics of natural polymer starch investigated by terahertz time-domain spectroscopy and low-frequency Raman scattering

Terahertz time-domain spectroscopy and low-frequency Raman scattering were performed on the natural polymer starch to investigate the boson peak (BP) dynamics. In the infrared spectrum, the BP was observed at 0.99 THz at the lowest temperature. Compared to the result from a previous study for vitreous glucose, both the frequency of the BP and absorption coefficient show lower values than those of the vitreous glucose. These behaviors originate from the longer correlation length of the medium-range order and lower concentration of hydroxyl groups in the starch. In the Raman spectrum, the BP was observed at 1.1 THz at room temperature, although the BP was not observed around room temperature due to the excess wing of the fast relaxation modes in the infrared spectrum. The temperature dependence of ε″(ν) during the heating process and cooling process shows a hysteresis below 230 K. During the heating process, kinks were observed at 140 K and 230 K. These kinks are attributed to the β-relaxation and the βwet-relaxation, respectively

Synthesis of functionalized insulated molecular wires by polymerization of an insulated π-conjugated monomer.

A new method for the synthesis of an insulated π-conjugated monomer was developed via the sequential self-inclusion followed by the elongation of the π-conjugated unit. The monomer was utilized in the synthesis of stimuli-responsive insulated molecular wires

Signaling Pathway of Histamine H1 Receptor-Mediated Histamine H1 Receptor Gene Upregulation Induced by Histamine in U-373 MG Cells

Histamine H1 receptor (H1R) is one of the targets of histamine in the nervous system and the peripheral tissues. Protein kinase Cδ (PKCδ) signaling is involved in histamine-induced upregulation of H1R gene expression in HeLa cells. Histamine also upregulates H1R gene expression in U-373 MG cells. However, the molecular signaling of this upregulation is still unclear. Here, we investigated the molecular mechanism of histamine-induced H1R gene upregulation in U-373 MG cells. Histamine-induced H1R gene upregulation was inhibited by H1R antagonist d-chlorpheniramine, but not by ranitidine, ciproxifan, or JNJ77777120, and H2R, H3R, or H4R antagonists, respectively. Ro-31-8220 and Go6976 also suppressed this upregulation, however, the PKCδ selective inhibitor rottlerin and the PKCβ selective inhibitor Ly333531 did not. Time-course studies showed distinct kinetics of H1R gene upregulation in U-373 MG cells from that in HeLa cells. A promoter assay revealed that the promoter region responsible for H1R gene upregulation in U-373 MG cells was different from that of HeLa cells. These data suggest that the H1R-activated H1R gene expression signaling pathway in U-373 MG cells is different from that in HeLa cells, possibly by using different promoters. The involvement of PKCα also suggests that compounds that target PKCδ could work as peripheral type H1R-selective inhibitors without a sedative effect

Regio- and Stereoselective Synthesis of Triarylalkene-Capped Rotaxanes via Palladium-Catalyzed Tandem Sonogashira/Hydroaryl Reaction of Terminal Alkynes

Triarylalkene-capped conjugated rotaxanes were synthesized via a palladium-catalyzed tandem Sonogashira/hydroaryl reaction between aryl halides and terminal alkynes bearing two permethylated α-cyclodextrins (PM α-CDs) with high regioselectivity because of the insulation effect of the PM α-CDs. Moreover, sequential Sonogashira coupling and hydroarylation reactions using different aryl substrates afforded a regio- and stereoselective trisubstituted alkene as a single product. This new class of rotaxane-forming reactions can be used to increase the diversity of rotaxane skeletons, and thereby the material functionalities of rotaxanes