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961.
Pereira AM Hausmann A Tomé JP Trukhina O Urbani M Neves MG Cavaleiro JA Guldi DM Torres T 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(11):3210-3219
The synthesis and photophysical properties of several porphyrin (P)-phthalocyanine (Pc) conjugates (P-Pc; 1-3) are described, in which the phthalocyanines are directly linked to the β-pyrrolic position of a meso-tetraphenylporphyrin. Photoinduced energy- and electron-transfer processes were studied through the preparation of H(2)P-ZnPc, ZnP-ZnPc, and PdP-ZnPc conjugates, and their assembly through metal coordination with two different pyridylfulleropyrrolidines (4 and 5). The resulting electron-donor-acceptor hybrids, which were formed by axial coordination of compounds 4 and 5 with the corresponding phthalocyanines, mimicked the fundamental processes of photosynthesis; that is, light harvesting, the transduction of excited-state energy, and unidirectional electron transfer. In particular, photophysical studies confirmed that intramolecular energy-transfer resulted from the S(2) excited state as well as from the S(1) excited state of the porphyrins to the energetically lower-lying phthalocyanines, followed by an intramolecular charge-transfer to yield P-Pc(.+)?C(60)(.-). This unique sequence of processes opens the way for solar-energy-conversion processes. 相似文献
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963.
Koc A Cañuelo A Garcia-Reyes JF Molina-Diaz A Trojanowicz M 《Journal of separation science》2012,35(12):1447-1461
In this work, the use of liquid chromatography coupled to electrospray time-of-flight mass spectrometry (LC-TOFMS) has been evaluated for the profiling of relatively low-molecular weight protein species in both genetically modified (GM) and non-GM maize. The proposed approach consisted of a straightforward sample fractionation with different water and ethanol-based buffer solutions followed by separation and detection of the protein species using liquid chromatography with a small particle size (1.8 μm) C(18) column and electrospray-time-of-flight mass spectrometry detection in the positive ionization mode. The fractionation of maize reference material containing different content of transgenic material (from 0 to 5% GM) led to five different fractions (albumins, globulins, zeins, zein-like glutelins, and glutelins), all of them containing different protein species (from 2 to 52 different species in each fraction). Some relevant differences in the quantity and types of protein species were observed in the different fractions of the reference material (with different GM contents) tested, thus revealing the potential use of the proposed approach for fast protein profiling and to detect tentative GMO markers in maize. 相似文献
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965.
Sousa J Alves G Abrantes J Fortuna A Falcão A 《Analytical and bioanalytical chemistry》2012,403(1):93-129
Fluoroquinolones are one of the most promising and intensively studied drugs of contemporary anti-infective chemotherapy.
New fluoroquinolone antibacterials with improved pharmacokinetic properties and a broad spectrum of activity have been developed,
opening new windows of opportunity for clinical use. To our knowledge, no comprehensive and critical review of the analytical
methods for the determination of these agents, which correspond to the third- and fourth-generation quinolones, has yet been
published. This work summarizes for the first time most of the liquid chromatographic methods reported in the literature for
the separation and quantification of the new fluoroquinolones in biological matrices and pharmaceutical formulations. A systematic
and detailed survey of physicochemical properties, sample preparation procedures, and chromatographic and detection conditions
is presented herein. In the course of this review several liquid chromatographic methods are discussed: reversed-phase high-performance
liquid chromatography (RP-HPLC), ion-exchange high-performance liquid chromatography (IEX-HPLC), hydrophilic interaction liquid
chromatography (HILIC), high-performance thin-layer chromatography (HPTLC) and other chiral chromatographic methods. Their
advantages, applicability and limitations are also examined. 相似文献
966.
Peng An Fang Zuo Yuan Peng Wu Jun Hua Zhang Zhao Hui Zheng Xiao Bin Ding Yu Xing Peng 《中国化学快报》2012,23(9):1099-1102
A fast approach was described for the synthesis of water-dispersible monodisperse dopamine-coated Fe3O4 nanoparticles(DA-Fe3O4) with uniform size and shape via ligand-exchange of oleic acid on Fe3O4 using only 2 min.The prepared DA-Fe3O4 nanoparticles were characterized by transmission electron microscopy,Fourier transform infrared spectrometry,and vibrating sample magnetometer.The results indicated that the resulting DA-Fe3O4 nanoparticles had an average diameter of about 19.2 nm. The magnetic saturation value of the prepared DA-Fe3O4 nanoparticles was determined to be 72.87 emu/g,which indicating a well-established superparamagnetic property. 相似文献
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FS Freitas JN Clifford E Palomares AF Nogueira 《Physical chemistry chemical physics : PCCP》2012,14(34):11990-11993
In this paper we focus on the effect of carboxylated thiophene small molecules as interface modifiers in TiO(2)/P3HT hybrid solar cells. Our results show that small differences in the chemical structure of these molecules, for example, the presence of the -CH(2)- group in the 2-thiopheneacetic acid (TAA), can greatly increase the TiO(2) surface wettability, improving the TiO(2)/polymer contact. This effect is important to enhance exciton splitting and charge separation. 相似文献