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91.
Double alkylated L-glutamide-derived noncrystalline stationary phases Sil-DSG and Sil-DBG have been prepared by coupling N',N'-dioctadecyl-N-[4-carboxybutanoyl]-L-glutamide (DSG) and N',N',-dibutyl-N-[4-carboxybutanoyl]-L-glutamide (DBG) with aminopropylated silica (Sil-APS). TEM observations of DSG and DBG showed that lipid DSG can aggregate in organic solvents (methanol, chloroform, toluene, etc.) and self-assembled nano fibers are observed while such fibrous aggregations are not observed for DBG. The resulting chromatographic data have been provided information about its selective interaction with guest molecules (PAHs) in RP-HPLC. We have observed that the carbonyl groups in Sil-DSG exist in ordered state by forming a condensing thin layer over silica surface while DBG cannot form such an ordered state due to its lower order of short alkyl chain. The ordered carbonyl groups present in Sil-DSG promotes multiple carbonyl pi-benzene pi interactions with guest PAHs isomers which enhance the selectivity for these compounds. The contribution of pi-pi interactions was also supported by the substantial effects on the selectivity of benzene and nitrobenzenes. The effect of pi-electron containing solvent on the retention behavior of the PAHs was also studied. The selectivity for nucleic acid constituents, i.e. nucleosides and its bases were also evaluated by Sil-DSG and the selectivity for these compounds on Sil-DSG was compared with the selectivity of conventional polymeric ODS phase. It has been found that Sil-DSG provided higher selectivity for nucleic acid constituents than polymeric ODS and that HPLC packing materials can be efficiently employed for routine analysis of these compounds. The effect of methanol content on the separation behavior of nucleosides was also studied. 相似文献
92.
Xue P Lu R Jia J Takafuji M Ihara H 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(12):3549-3558
A gelator that consisted of one benzimidazole moiety and four amide units was used as a chemosensor. We found that its absorption and emission spectra in solution were sensitive to two complementary chemical stimuli: protons and anions. Thus, YES and INH logic gates were obtained when absorbance was defined as an output. A combination gate of XNOR and AND with an emission output was also obtained. Moreover, wet gels in two solvents were used to construct two more-complicated three-input-three-output gates, owing to the existence of the gel phase as an additional output. Finally, in xerogel films that were formed from two kinds of wet gels, reversible changes in their emission spectra were observed when they were sequentially exposed to volatile acid and NH(3). Another combination two-output logic gate was obtained for xerogel films. Finally, three states of the gelator were used to construct not only basic logic gate, but also some combination gates because of their response to multiple chemical stimuli and their multiple output signals, in which one chemical input could erase the effect of another chemical input. 相似文献
93.
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95.
We have developed a method to analyze the substrate transport of ATP-binding cassette (ABC) transporters, which are associated with drug resistance in tumor cells. Our microfluidic method is well suited to the single-vesicle estimation of substrate transport and the rapid drug screening of ABC transporters. Using this method, we have demonstrated, for the first time, the analysis of substrate transport by a single transporter and performed drug-inhibition experiments in less than 3 h. 相似文献
96.
Nakano H Nakano M Nakanishi K Tanaka D Sugiyama Y Ikuno T Okamoto H Ohta T 《Journal of the American Chemical Society》2012,134(12):5452-5455
Alkyl-modified crystalline silicon nanosheets 2 were synthesized and maintained the crystal structure of a Si(111) plane, in which the dangling silicon bond is stabilized by capping with the alkyl group. 2 was characterized using UV-vis, Fourier transform-infrared, and X-ray photoelectron spectroscopies; X-ray diffraction; and X-ray absorption near edge structure analysis. A model structure is proposed that has a periodicity through the nanosheet surface. 相似文献
97.
Hirotaka Ogawa Akinori Kan Norihiro Ikeda Akihiro Fujita 《Physica B: Condensed Matter》2012,407(21):4308-4312
The effect of In doping on the electroluminescence (EL) properties of Zn2SiO4:In thin films was investigated. In-doped Zn2SiO4 thin films were deposited on BaTiO3 substrates and their EL properties were characterized in this study. X-ray powder diffraction patterns of In-doped Zn2SiO4 powders revealed a single phase of Zn2SiO4 for In concentrations up to approximately 1.5 mol%, whereas a secondary phase of In2O3 was observed for In concentrations in the range of 2–10 mol%. The maximum luminance of thin film electroluminescent (TFEL) devices varied significantly with the amount of In doping. The highest luminance with blue emission was obtained when 2 mol% In was doped. The blue emission of In-doped Zn2SiO4 thin film may be related to the In substitution for Zn. The 2 mol% In-doped Zn2SiO4 thin film exhibited blue emission with CIE color coordinates of x=0.208 and y=0.086. 相似文献
98.
5,10,15‐Tris(pentafluorophenyl)tetrapyrromethane was efficiently prepared through a route involving stepwise diaroylation of 5‐pentafluorophenyldipyrromethane. A2B6‐type [36]octaphyrins were prepared by the cross condensation of the tetrapyrromethane with aryl aldehydes in moderate yields. A2B6‐type [36]octaphyrins bearing 2,4,6‐trifluorophenyl, 2,6‐dichlorophenyl, and phenyl substituents underwent CuII‐metalation‐induced fragmentation to give two molecules of AB3‐type CuII porphyrins. A2B6‐type [36]octaphyrin bearing 3‐thienyl substituents underwent thermal N‐thienyl fusion reactions to provide a modestly aromatic [38]octaphyrin, which, upon treatment with MnO2, underwent further N‐thienyl fusion and subsequent oxidation to give a nonaromatic doubly N‐thienyl fused [36]octaphyrin. 相似文献
99.
Shimoda K Kubota N Hirano H Matsumoto M Hamada H Hamada H 《Natural product communications》2012,7(4):529-530
Cultured plant cells of Marchantia polymorpha, Nicotiana tabacum, Phytolacca americana, Catharanthus roseus, and Gossypium hirsutum were examined for their ability to reduce curcumin. Only M. polymorpha cells converted curcumin into tetrahydrocurcumin in 90% yield in one day. Time-course experiment revealed a two-step formation of tetrahydrocurcumin via dihydrocurcumin. 相似文献
100.
Here, we present the first application of molecular gel-mediated power-conversion enhancement of solar cells, which is based on the excimer emission from a transparent and colourless polymer film that encapsulates a pyrene nano-fibrillar assembly. 相似文献