Cationic nanoparticles （NPs） for gene delivery were successfully prepared by assembling earboxylation poly（lactic-co-glycolic acid） （PLGA）, polyethylene glycol （PEG）, L-ct-Phosphatidylethanolamine （DOPE） and octadecyl quaternized carboxymethyl chitosans （OQCMC）. Lactoferrin （Lf） was selected as a targeting ligand conjugated to PLGA via bifunctional PEG, yielding PLGA-PEG-Lf/DOPE NPs to be used for gene vectors. Fourier transform infrared spectroscopy （FTIR）, UV and nuclear magnetic resonance （NMR） spectroscopy were performed to evaluate the synthesis of the vectors. The characteristics of the vectors loaded heine oxygenase （HO-1） gene were evaluated by transmission electron microscope （TEM）, particle size analyser and fluorescent microscopy. The experimental results showed that the obtained vectors were spherical in shape with average particle size of 142.2 nm and zeta potentials of ＋16.4 inV. The vectors could protect the loaded gene from the degradation by nuclease. For 293T cells, there is high transfection efficiency of the vectors similar to liposome-2000. It can be concluded that the established cationic PLGA-PEG-Lf/DOPE NPs have potential gene delivery ability for gene therapy.
Ta2O5 films are prepared by e-beam evaporation with varied deposition temperatures, annealing temperatures, and annealing times. The effects of temperature on the optical properties, chemical composition, structure, and laser- induced damage threshold （LIDT） are systematically investigated. The results show that the increase of deposition temperature decreases the film transmittance slightly, yet annealing below 923 K is beneficial for the transmittance. The XRD analysis reveals that the film is in the amorphous phase when annealed below 873 K and in thehexagonal phase when annealed at 1073 K. While an interesting near-crystalline phase is found when annealed at 923 K. The LIDT increases with the deposition temperature increasing, whereas it increases firstly and then decreases as the annealing temperature increases. In addition, the increase of the annealing time from 4 h to 12 h is favourable to improving the LIDT, which is mainly due to the improvement of the O/Ta ratio. The highest LIDT film is obtained when annealed at 923 K, owing to the lowest density of defect.
A virtual sieving experimental simulation system was built using physical simulation principles.The effects of vibration frequency and amplitude,the inclination angle of the screen-deck and the vibration direction angle of screen on single particle kinematics were predicted.Properties such as the average velocity and the average throw height were studied.The results show that the amplitude and the angle of vibration have a great effect on particle average velocity and average height.The vibration frequency and the screen-deck inclination angle appear to have little influence on these responses.For materials that are difficult to screen the vibration frequency and amplitude,the screen-deck inclination angle and the vibration angle should be set to 14 Hz,6.6 mm,6° and 40°,respectively,to obtain optimal particle kinematics.A screening process can be simulated reliably by means of a virtual experiment and these results provide references for both screening theory research and sieving practice.
A series of CoxMn0.06/SiO2 catalysts were prepared by an impregnation method for catalytic hydrogenation of CO to Light Hydrocarbons(LHCs).The catalysts were characterized by XRD,SEM,N2 adsorption and NH3-TPD techniques.Catalyst activities were evaluated in a high-pressure micro reactor.The results show that the performance of the catalysts was significantly affected by the amount of Co loaded onto the substrate.The activity of the Co0.10Mn0.06/SiO2 catalyst was stable with time-on-stream.The CO conversion and LHCs selectivity were 95.3% and 98.1%,respectively,for this catalyst at 400 °C.
