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We analyse the evolution of a two-stage chemical reaction betweentwo neighbouring plumes of reactants. Under the assumption thatthe plumes are approximately Gaussian we derive a system ofordinary differential equations for the total amount, the centroidand the variance of each reactant. We compare the solution ofthese equations with full numerical simulation of the reaction.Excellent agreement is obtained, with solution of the near-Gaussianmodel requiring considerably less computational effort thanthe full simulations. Of key importance is the yield of thereaction, and we discuss this feature in particular. 相似文献
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K. V. Katti R. Kannan K. Katti V. Kattumori R. Pandrapraganda V. Rahing C. Cutler E. J. Boote S. W. Casteel C. J. Smith J. D. Robertson S. S. Jurrison 《Czechoslovak Journal of Physics》2006,56(1):D23-D34
Metallic nanoparticles, because of their size, chemical and physical properties, are particularly attractive as therapeutic
probes in treating cancer. Central to any clinical advances in nanoparticulate based therapy will be to produce hybrid nanoparticles
that can be targeted to vascular, extracellular or cell surface receptors. Development of hybrid nanoparticles that specifically
target cancer vasculature has received considerable attention. Most cancers have leaky vasculature and the defective vascular
architecture, created due to the rapid vascularization necessary to serve fast growing cancers, in combination with poor lymphatic
drainage allows increased permeation and retention effects. The leaky vasculature, because of higher porosity and permeability,
serve as natural high affinity targets to metallic nanoparticles. Another attractive approach toward the application of nanotechnology
to nanomedicine is the utility of nanoparticles that display inherent therapeutic properties. For example radioactive gold
nanoparticles present attractive prospects in therapy of cancer. The radioactive properties of Au-198 (βmax=0.96 MeV; t1/2=2.7 d) and Au-199 (βmax=0.46 MeV; t1/2=3.14 d) make them ideal candidates for use in radiotherapeutic applications. In addition, they both have imageable gamma
emissions for dosimetry and pharmacokinetic studies and Au-199 can be made carrier-free by indirect methods. Gold nanoparticles
are of interest for treatment of disease as they can deliver agents directly into cells and cellular components with a higher
concentration of radioactivity, e.g. higher dose of radioactivity, to cancerous tumor cells. 相似文献
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SL Mironov E Skorova G Taschenberger N Hartelt VO Nikolaev MJ Lohse S Kügler 《BMC neuroscience》2009,10(1):29-11
Background
cAMP is an ubiquitous second messenger mediating various neuronal functions, often as a consequence of increased intracellular Ca2+ levels. While imaging of calcium is commonly used in neuroscience applications, probing for cAMP levels has not yet been performed in living vertebrate neuronal tissue before. 相似文献35.
Kannan R Rahing V Cutler C Pandrapragada R Katti KK Kattumuri V Robertson JD Casteel SJ Jurisson S Smith C Boote E Katti KV 《Journal of the American Chemical Society》2006,128(35):11342-11343
Nanocompatible chemistry which utilizes a novel nontoxic phosphino amino acid as a reducing agent has resulted in the development of therapeutically useful gold nanoparticles under biologically benign media. Stabilization of gold nanoparticles by the edible gum arabic matrix has provided an effective pathway toward in vivo stable target-specific gold nanoparticles. 相似文献
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MJ Lazaro AA Herod M Domin Y Zhuo CA Islas R Kandiyoti 《Rapid communications in mass spectrometry : RCM》1999,13(14):1401-1412
Three methods for determining a 'safe' estimate for high-mass limits of MALDI spectra of coal derived liquids were explored, using a sample of coal-tar pitch and its pyridine-insoluble fraction. Co-addition of increasing numbers of single-shot spectra (10, 30, 50 and 100 pulses) showed visually observable reductions in noise levels, consistent with robust and statistically meaningful signals. Three separate types of post-acquisition calculation were used to identify high-mass limits of the spectra. (i) A literature method indicated high-mass limits similar to those observed visually-as a shift from baseline at the highest masses, nearly 350 000 u for the coal tar pitch and about 390 000 u for its pyridine insoluble fraction. (ii) Comparing instrument signal with pre-selected multiples of the standard deviation, upper mass estimates of between 40-60 000 u for the coal-tar pitch and about 95 000 u for its pyridine-insoluble fraction were found. (iii) Calculation of the slope was used to identify 'lift-off' of the spectrum from baseline. The angle between the smoothed spectrum and the baseline was matched to a pre-selected value (e.g. 0.5 degrees and 1 degrees ). However, the arbitrary specification of the key parameter did not establish this last method on a firm basis. The choice of a criterion for estimating high-mass limits of MALDI spectra remains a semi-quantitative procedure; a reasonably conservative high-mass limit may be estimated by comparison of signal with five times the standard deviation. However, evaluation of size exclusion chromatograms of the present samples using polystyrene standards suggests that molecular mass distributions of pitch samples arrived at by MALDI mass spectrometry are, at least partly, determined by the limitations of available instruments. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
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Van Bael MJ Bekaert J Temst K Van Look L Moshchalkov VV Bruynseraede Y Howells GD Grigorenko AN Bending SJ Borghs G 《Physical review letters》2001,86(1):155-158
A scanning Hall probe microscope is used to study flux pinning in a thin superconducting Pb film covering a square array of single-domain Co dots with in-plane magnetization. We show that single flux quanta of opposite sign thread the superconducting film below T(c) at the opposite poles of these dipoles. Depending on the polarity of the applied field, flux lines are attracted to a specific pole of the dipoles, due to the direct interaction with the vortexlike structures induced by the local stray field. 相似文献
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Peroxy natural products. 总被引:1,自引:0,他引:1
D A Casteel 《Natural product reports》1992,9(4):289-312
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