排序方式: 共有44条查询结果,搜索用时 467 毫秒
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Andrew M. Edmonds Mushtaq A. Sobhan Varun K. A. Sreenivasan Ekaterina A. Grebenik James R. Rabeau Ewa M. Goldys Andrei V. Zvyagin 《Particle & Particle Systems Characterization》2013,30(6):506-513
Bioprobes based on fluorescent ruby nanoparticles, which are suitable for ultrasensitive imaging, are reported. A stable aqueous/buffer colloid, permitting facile conjugation to proteins, is produced by femtosecond laser ablation of ruby and the nanoparticles (mean size 17 nm) are photostable, with long lifetime (1–4 ms) 694 nm emission. With time‐gating complete (>20 dB) suppression of cell autofluorescence and suppression of exogenous fluorophores is observed. Nanoparticles are imaged in as‐grown cells and those immunolabeled with quantum dots. Immunoassay binding to target biomolecules is also demonstrated. 相似文献
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Mushtaq A. Sobhan Martin Ams Michael J. Withford Ewa M. Goldys 《Journal of nanoparticle research》2010,12(8):2831-2842
Previous studies investigating the role of the operating parameters on ultrafast laser ablative generation of gold nanoparticles have reported a wide range of nanoparticle size distribution and plasmon resonant properties. In some cases the reported role of fluence and other processing parameters is contradictory. In this systematic investigation, we deconstruct and examine the role of the component parts of fluence, namely pulse energy and ablation spot size, on nanoparticle generation. Other parameters such as exposure time and scan speed are also studied. We show that the nanoparticle average size and distribution is related to different contributions from pulse energy, pulse repetition frequency and spot size. We also correlate the average particle size and distribution with the wavelength and width of the plasmon resonance peak, and apply Mie theory in order to develop clearer physical insights into the mechanisms dominating nanoparticle generation. 相似文献
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Zdzisław Brzeźniak Ben Goldys Peter Imkeller Szymon Peszat Enrico Priola Jerzy Zabczyk 《Comptes Rendus Mathematique》2010,348(5-6):273-276
This Note is concerned with the properties of solutions to a linear evolution equation perturbed by a cylindrical Lévy process. It turns out that solutions, under rather weak requirements, do not have a càdlàg modification. Some natural open questions are also stated. 相似文献
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Alistair J.M. Farley Pavol Jakubec Anna M. Goldys Darren J. Dixon 《Tetrahedron》2018,74(38):5206-5212
Bifunctional iminophosphorane (BIMP) organocatalysts catalyze the enantio- and diastereoselective Michael additions of high pKa cyclic malonamate ester pro-nucleophiles to nitroalkenes with reactivity profiles of up to 3 orders of magnitude greater than tertiary amine bifunctional Brønsted base/(thio)urea organocatalysts. The unrivalled performance of the BIMPs allows reaction times of challenging reactions to be slashed from weeks to minutes and has enabled new flow chemistry applications using polystyrene-supported versions contained within a flow reactor. 相似文献
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Fluorescence amplification by electrochemically deposited silver nanowires with fractal architecture
Goldys EM Drozdowicz-Tomsia K Xie F Shtoyko T Matveeva E Gryczynski I Gryczynski Z 《Journal of the American Chemical Society》2007,129(40):12117-12122
Electrochemically deposited silver structures with nanowires 50-100 nm in diameter show high fluorescence amplification and strongly reduced fluorescence lifetimes. Both quantities depend on the structure thickness. With increasing thickness the fluorescence amplification proportionally increases and the fluorescence lifetime decreases. This thickness dependence is caused by fluorophore interaction with a system of plasmon excitations in coupled nanowires extending over micrometer size regions. Thus the amplification is attributed to a combination of extended structure area and strong plasmonic coupling between nanowires which also help to radiatively scatter the fluorescence emission. 相似文献
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Anna Goldys 《Tetrahedron letters》2009,50(27):3985-480
Microwave-assisted Suzuki cross-coupling between 2,2′-bis(methoxymethyl)-3,3′-bis(potassium trifluoroboronato)BINOL and a series of 2-bromo- or 2-chloropyridines provides efficient access to 3,3′-dipyridyl BINOL ligands. 相似文献
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Goldys EM Drozdowicz-Tomsia K Jinjun S Dosev D Kennedy IM Yatsunenko S Godlewski M 《Journal of the American Chemical Society》2006,128(45):14498-14505
Rare-earth-doped nanoparticles are promising materials for fluorescent labeling, as they are characterized by a high Stokes shift, narrow emission spectra, long lifetimes, minimized photobleaching, and low toxicity. We examined the structural and optical properties of europium-doped gadolinium oxide nanoparticles synthesized by the flame pyrolysis method, with specific emphasis on full spectral characterization and fluorescence kinetics. The emission-excitation characterization revealed the presence of predominantly monoclinic but also highly luminescent cubic phases with a prominent oxygen-to-europium charge-transfer band in the 230-260 nm range. A broad emission band in the visible region, corresponding to a similar band in undoped Gd(2)O(3), related to the matrix surface defects, was observed in time-gated spectroscopy of doped nanopowders. All of the examined nanopowders showed very short decay components, on the order of 2 ns, and much longer millisecond decay times characteristic of lanthanide ions. At intermediate times, on the order of 20-100 ns, a complex behavior of the decay was observed, indicative of progressive energy transfer to the lanthanide ion, which varied with different intrashell transitions. Structural characterization data by means of XRD measurements allowed for unambiguous determination of the Eu:Gd(2)O(3) crystallographic structure and cell dimensions to be consistent with a predominantly monoclinic phase. 相似文献
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