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81.
82.
Cover Picture: Electron‐transfer transparency of graphene: Fast reduction of metal ions on graphene‐covered donor surfaces (Phys. Status Solidi RRL 3/2015) 下载免费PDF全文
83.
Hee‐Cheul Kim Sun‐Kuk Kim Jeong Tai Kim Kyong‐Yop Rhee John Kathi 《Journal of Polymer Science.Polymer Physics》2010,48(11):1175-1184
Multiwalled carbon nanotubes (MWCNTs) were oxidized using four different acid‐treatment methods followed by their functionalization with 3‐aminopropyltriethoxysilane (3‐APTES). Diglycidyl ether of bisphenol A (DGEBA) nanocomposites with unmodified and silanized MWCNTs (0.2 wt %) were prepared by a cast molding method. The effect of functionalization of MWCNTs on thermal, flexural, and morphological properties of the epoxy nanocomposites were studied. The epoxy/MWCNTs nanocomposites were characterized by thermogravimetric analysis, flexural testing, and field emission electron microscopic analysis. The results showed that the silanization of MWCNTs which were oxidized by a two‐step process using nitric acid and hydrochloric acid showed better thermal and flexural properties due to good interfacial adhesion between MWCNTs and the epoxy matrix. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 1175–1184, 2010 相似文献
84.
Sang-Hee Chung Sung-Kuk Kim Jung Kuk Kim Yong-Ryoul Yang Pann-Ghill Suh Jong-Soo Chang 《Experimental & molecular medicine》2010,42(3):216-222
Growth factor stimulation induces Y783 phosphorylation of phosphoinositide-specific PLC-γ1, and the subsequent activation of this enzyme in a cellular signaling cascade. Previously, we showed that a double point mutation, Y509A/F510A, of PLC-γ1, abolished interactions with translational elongation factor 1-α. Here, we report that the Y509A/F510A mutant PLC-γ1 displayed extremely high levels of Y783 phosphorylation and enhanced catalytic activity, compared to wild-type PLC-γ1, upon treatment of COS7 cells with EGF. In quiescent COS7 cells, the Y509A/F510A mutant PLC-γ1 exhibited a constitutive hydrolytic activity, whereas the wild-type counterpart displayed a basal level of activity. Upon treatment of COS7 cells with EGF, the Y783F mutation in Y509A/F510A PLC-γ1 (Y509A/F510A/Y783F triple mutant) cells also led to an enhanced catalytic activity, whereas Y783F mutation alone displayed a basal level of activity. Our results collectively suggest that the Y509A/F510A mutant is more susceptible to receptor tyrosine kinase-induced Y783 phosphorylation than is wild-type PLC-γ1, but no longer requires Y783 phosphorylation step for the Y509A/F510A mutant PLC-γ1 activation in vivo. 相似文献
85.
A new calix[4]arene-based fluorescence chemosensor displaying a strong excimer emission was prepared. When a Pb2+ ion is bound to the two amide oxygen atoms linked to the fluorophores, the ligand exhibits a marked quenched excimer emission due to its geometrical change during the complexation. By the addition of Ca2+ ion into the 1·Pb2+, the excimer emission band was revived, by which an interesting on/off switch process is proposed. 相似文献
86.
Jung SH Park SY Kim-Pak Y Lee HK Park KS Shin KH Ohuchi K Shin HK Keum SR Lim SS 《Chemical & pharmaceutical bulletin》2006,54(3):368-371
Fifteen chalcones and three thiazolidinedione (TZD) chalcones were prepared to evaluate their peroxisome proliferator-activated receptor-gamma (PPAR-gamma) ligand-binding activities. Among the three TZDs, one compound possessed PPAR-gamma transactivation potential, while the others showed antagonistic activity against PPAR-gamma transactivation. Among the chalcones, compound 5 was the most potent, and structure-activity relationship studies indicated that a methoxyl group in position C-4 and hydroxyl group in position C-4' or 5' in chalcone plays a key role in determining the potency of PPAR-gamma activation. 相似文献
87.
Bifunctional (fluorescence and visible light absorption) anion-sensing compounds 1 and 2 based on calix[4]arene platform with 4-nitrophenylazo and pyrene moieties have been developed. The two NHs of the amide groups of 1 bind the fluoride anion through the H-bonding. This changes the characteristic excimer emission and forms a new emission peak from a static excimer. In 2, two OHs bind the fluoride anion, and this changes the characteristic absorption spectrum. The DFT calculation supports the regioselective binding of the fluoride anion, which is responsible for the different sensing property. 相似文献
88.
89.
YoungKwan Park SangBeom Choi Hyunuk Kim Kimoon Kim Byoung‐Ho Won Kihang Choi Jung‐Sik Choi Wha‐Seung Ahn Nayoun Won Sungjee Kim DongHyun Jung Seung‐Hoon Choi Ghyung‐Hwa Kim Sun‐Shin Cha YoungHo Jhon JinKuk Yang Jaheon Kim 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2007,119(43):8378-8381
90.
Charge transfer (CT) resonance mechanisms of 2,2′‐bipyridine (2,2′‐BiPy), 2,4′‐bipyridine (2,4′‐BiPy), and 4,4′‐bipyridine (4,4′‐BiPy) on silver nanoparticle surfaces have been comparatively investigated by means of surface‐enhanced Raman scattering (SERS) at the excitation wavelengths of 457, 514, 633, and 785 nm. A combination of the electromagnetic (EM) and charge transfer (CT) contributions should affect the SERS intensities for the bipyridine compounds adsorbed on silver nanoparticle surfaces. The CT resonance is assumed to occur in dissimilar ways for the bipyridine compounds, as evidenced from their different excitation‐wavelength‐dependent SERS enhancement factors. Ab initio density functional theory (DFT) calculations at the level of B3LYP/LANL2DZ have been carried out for the bipyridine‐Ag complexes. Copyright © 2007 John Wiley & Sons, Ltd. 相似文献