778 research outputs found

    Magnetic Resonance imaging (MRI) in detection of _Bifidobacterium longum_ and _Clostridium novyi-NT_ labeled with superparamagnetic iron oxide (SPIO) nanoparticle

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    *Purpose:* To investigate the MR imaging of _Bifidobacterium longum_ and _Clostridium novyi-NT_ labeling with superparamagnetic iron oxide (SPIO) nanoparticles.

*Materials and methods:* Tubes containing _B. longum_-SPIO, Free-SPIO, _B. longum_ and PYG Medium were incubated under anaerobic condition in _in vitro_ experiment. Transmission electron microscope and Prussian blue staining were used to demonstrate intra-bacteria nanoparticles. R~2~^*^ mapping and R~2~ mapping were reconstructed after MR scanning. _B. longum_-SPIO and _C. novyi_-NT-SPIO were injected respectively _in vivo_ to show whether it might be traced by MR imaging.

*Results:* Magnetosomes in bacteria were observed by electron microscopic and stained by Prussian blue staining. At the same concentration of SPIOs, the R~2~^*^ value of _B. longum_-SPIO was significantly higher than that of Free-SPIO (P<0.001), however, the R~2~ value was lower comparing with Free-SPIO (P<0.001). After injection with _B. longum_-SPIO, they could present in tumor and shorten T~2~^*^.

*Conclusion:* _B. longum_ and _C. novyi_-NT could be labeled by SPIO and then traced by MRI

    Continuous fabrication of calcium sulfate whiskers with adjustable aspect ratio in microdroplets

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    Hemi-hydrate and anhydrous CaSO₄ whiskers with adjustable aspect ratio were continuously synthesized by the reactive crystallization of CaCl₂ to K₂ S₂ O₈ in microdroplets. The effects of solvent and reactive temperature were examined, with SEM and XRD characterizations. Hemi-hydrate and anhydrous CaSO₄ whiskers can be, respectively, obtained in aqueous and N,N-dimethylformamide solutions at 90 °C in 180 s. The addition of ethylene glycol or glycerol as well as increasing temperature could lead to the increase in length and aspect ratio of the whiskers. Thus this preparation technique provides a simple continuous route to synthesize CaSO₄ whiskers with two kinds of crystal structures in a short time, and adjustable lengths and aspect ratios

    Composite Cyclotomic Fourier Transforms with Reduced Complexities

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    Discrete Fourier transforms~(DFTs) over finite fields have widespread applications in digital communication and storage systems. Hence, reducing the computational complexities of DFTs is of great significance. Recently proposed cyclotomic fast Fourier transforms (CFFTs) are promising due to their low multiplicative complexities. Unfortunately, there are two issues with CFFTs: (1) they rely on efficient short cyclic convolution algorithms, which has not been investigated thoroughly yet, and (2) they have very high additive complexities when directly implemented. In this paper, we address both issues. One of the main contributions of this paper is efficient bilinear 11-point cyclic convolution algorithms, which allow us to construct CFFTs over GF(211)(2^{11}). The other main contribution of this paper is that we propose composite cyclotomic Fourier transforms (CCFTs). In comparison to previously proposed fast Fourier transforms, our CCFTs achieve lower overall complexities for moderate to long lengths, and the improvement significantly increases as the length grows. Our 2047-point and 4095-point CCFTs are also first efficient DFTs of such lengths to the best of our knowledge. Finally, our CCFTs are also advantageous for hardware implementations due to their regular and modular structure.Comment: submitted to IEEE trans on Signal Processin

    Elaboration and characterization of nanoplate structured alpha-Fe2O3 films by Ag3PO4

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    A new strategy for surface treatment of hematite nanoplates for efficient photoelectrochemical (PEC) performances is proposed. Silver orthophosphate (Ag₃PO₄) has been adopted to mediate the formation of α-Fe₂O₃ films. Phosphate ions in Ag₃PO₄ is found to cause a significant morphology change during annealing process, from β-FeOOH nanorod arrays to hematite nanoplates. Meanwhile, Ag ions is doped into α-Fe₂O₃ film. The obtained nanoplate structured Fe₂O₃ –Ag–P films demonstrate much higher photoelectrochemical performance as photoanodes than the bare Fe₂O₃ nanorod thin films. The effects of phosphate and silver ions on the morphology, surface characteristics and the PEC properties of the photoanodes are investigated

    Synergistic effect on co-pyrolysis of capsicum stalks and coal

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    With the depletion of fossil fuel and the concern about environmental issues, the utilization of biomass resources has attracted increasing worldwide interest. The pyrolysis behavior of capsicum stalks and Baoji coal mixtures was investigated by TG-DSC. Results show that the thermal degradation temperature range of capsicum stalks was 290 to 387°C, while that of Baoji coal was 416 to 586°C. According to the comparison of experimental values and calculation results based on the algebraic sum of the fraction of individual mixture samples, the synergistic effect was significant at temperature ranges of 314 to 369 and 431 to 578°C. The synergistic effect could also be seen from the kinetic studies performed according to the Fried man Method. The rate of mass loss and k in the experiment is higher than the calculated values in the range of 314 to 368°C and that in the experiment is lower than the calculated values in the range of 431 to 578°C. Meanwhile, it was indicated that the pyrolysis process of capsicum stalks, Baoji coal and their mixtures could be described by one, two and four first order reactions, respectively.Keywords: Pyrolysis, capsicum stalks, mixing rate, kinetics, synergistic effec

    Nonlinear Inertia Classification Model and Application

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    Classification model of support vector machine (SVM) overcomes the problem of a big number of samples. But the kernel parameter and the punishment factor have great influence on the quality of SVM model. Particle swarm optimization (PSO) is an evolutionary search algorithm based on the swarm intelligence, which is suitable for parameter optimization. Accordingly, a nonlinear inertia convergence classification model (NICCM) is proposed after the nonlinear inertia convergence (NICPSO) is developed in this paper. The velocity of NICPSO is firstly defined as the weighted velocity of the inertia PSO, and the inertia factor is selected to be a nonlinear function. NICPSO is used to optimize the kernel parameter and a punishment factor of SVM. Then, NICCM classifier is trained by using the optical punishment factor and the optical kernel parameter that comes from the optimal particle. Finally, NICCM is applied to the classification of the normal state and fault states of online power cable. It is experimentally proved that the iteration number for the proposed NICPSO to reach the optimal position decreases from 15 to 5 compared with PSO; the training duration is decreased by 0.0052 s and the recognition precision is increased by 4.12% compared with SVM
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