紫色非硫细菌质粒的制备与性质

介绍一种适于紫色非硫细菌质粒的制各方法，该法简单，易操作，质粒DNA纯度好，收率高，通过在加富培养基上连续传代数次，质粒DNA可自行消除。

Research on the Construction of Bacterial Artificial Chromosome Vector DNA and the Potentials in Application

[ Objective] The aim of this study was to provide a method for solving the problems in preparing BAC vector with High-copy plasmid pUC119- Bluelox BAC. [ Method ] With selecting a proper single restriction site, sequences of a single copy BAC vector plasmid were inserted into proper site of High-copy plasmid pUC119 vector. [ Result] The gene sequence of BAC vector lost control function of single copy number in new plasmid pUC119-BAC and was copied through High-copy form. The gene sequence of BAC vector basic function was completely cutted off through single enzyme digestion and the control function of single copy could be recovered by auto-connection. [ Conclusion] The High-copy pUC119-BAC plasmid was used to copy and amplify high copy of basic function gene sequence in BAC vector, besides that it could be used to construct transfer vector of molecular cloned recombinant virus or BAC library.

Preparation and Crystal Modification of Ibuprofen-Loaded Solid Lipid Microparticles

An emulsion-congealing technique is used to prepare solid lipid microparticles （SLM） containing ibuprofen with glyceryl behenate, tripalmitin and beewax as excipients. The difference of the solubility parameters between the excipients and ibuprofen are used to analyze their compatibility. Both the solubility parameter analysis and the experimental results show that glyceryl behenate is the best among the three excipients. The solid particles disperse well in aqueous phase when the drug loading reaches 10% （relative to lipid only）. Glycerides exhibit marked polymorphism and their rapid rates of crystallization accelerate the formation of metastable crystal modification. The metastable crystal modification characterizes high drug loading capacity but less stability. Increasing the content of lipophilic drug in a lipid matrix facilitates the transformation of excipients to more stable polymorphic forms.

Preparation of amorphous nano-boron powder with high activity by combustion synthesis

The preparation process of amorphous nanometer boron powders through combustion synthesis was investigated, and the effects of the reactant ratio, the heating agent and the milling rate on the activity and particle size of amorphous boron powders were studied. The results show that the boron powders exist in the form of an amorphous phase which has the crystallinity lower than 30.4%, and the panicle size of boron powder decreases with an increase of the high-energy ball milling rate. The purity of amorphous boron powder is 94.8% and panicle sizes are much smaller than 100 nm when the mass ratio of B2O3/Mg/KClO3 is 100：105：17 and the ball milling time is 20 min with the milling rate of 300 r/min. At the same time, the amorphous boron nano-fibers appear in the boron powders.

Comparative study on photocatalytic properties of TiO_2 nanoparticles prepared in acidic medium and basic medium by hydrothermal method

In order to investigate the difference of phtotocatalytic properties of TiO2 samples prepared in different pH conditions, TiO2 nanopartieles were prepared in acidic medium and basic medium by a hydrothermal process, respectively. The samples were characterized using XRD, TEM, BET, XPS, surface photovoltage spectroscopy （SPS） and field-induced surface photovohage spectroscopy （FISPS）. Effects of temperature and pH in the hydrothermal process on particle sizes, specific surface areas, and photoeatalytic properties of the TiO2 nanoerystalline were investigated. The experimental results indicate that the photocatalysis activity of TiO2 nanoparticles prepared in basic medium （ B-TiO2 ） is superior to that in acidic medium （ A-TiO2 ）, which is ascribed to the difference of surface state between A-TiO2 and B-TiO2.

Preparation and characterization of oleanolic acid-loaded solid lipid nanoparticles for oral administration

Oleanolic acid-loaded solid lipid nanoparticles（OA-SLNs）were prepared by using an improved emulsion-solvent evaporation method.The size,zeta potential,encapsulation efficiency,and loading efficiency of OA-SLNs were（104.5±11.7）nm, （-25.5±1.8）mV,（94.2±3.9）%,and（4.71±0.15）%,respectively.The morphology was illustrated by TEM as sphere stuffed particles.The XRD and DSC spectra confirmed that the OA molecules were dispersed uniformly into SLN matrixes.The results of in vitro release test suggested that OA was released slowly at a rate of 4.88%per hour from SLN preparation,which was consistent with the Zero-order Released Model.In addition,OA-SLNs were stable in artificial gastric juice and artificial intestinal juice.Together,our results provided new data for the potential application of OA-SLNs in oral administration.

Preparation and characterization of budesonide-loaded solid lipid nanoparticles for pulmonary delivery

To increase the solubility and adsorption of budesonide（BUD）,budesonide-loaded solid lipid nanoparticles（BUD-SLNs） were prepared and characterized in this study.Glycerin monostearate（GMS）was selected to be the matrix lipid material after calculation the differences of partial solubility parameters.An emulsification-ultrasound diffusion method was employed and formula was optimized in the BUD-SLNs preparation.The entrapment efficiency（ee%）of BUD-SLNs was（97.77±2.60）%, and the mean particle size was 147.3 nm（PDI=0.228）.Uniform and sphere particles were observed under TEM.The in vitro release of BUD-SLNs could be well explained by the biphasic release dynamics equation.The spectrums of DSC and X-ray diffraction indicated that BUD molecules were dispersed mainly into the lipids to form homogeneous matrix structure.Our results provide fundamental data for the application of SLNs in pulmonary delivery system.

Magnetic properties and magnetoresistance of Co_xC_(1-x) granular films prepared by magnetron sputtering

Amorphous CoxC1-x granular films were prepared on n-Si（100） substrate by dc magnetron sputtering. The effects of Co con- centration, film thickness and annealing temperature on the magnetic properties and magnetoresistance （MR） were investigated After annealing at 500℃ for 0.5 hour, the Co（002） peak of the CoxC1-x（x〉2.5 at.%） films was observed, but cracks appeared in the films. Saturation magnetization Ms increased steadily with the increase of Co concentration from 2.5 at.% to 50 at.% and also increased with annealing temperature from room temperature to 400℃. The coercivity of CoxC1-x films was less than 180 Oe. The as-deposited Co2.5C97.5 granular films with 80 nm thickness showed a highly positive MR, up to 15.5% at a magnetic field of 0.8 T, observed at T=300 K when the external magnetic field was perpendicular to the film surface. With increasing film thickness and annealing temperature, the value of MR was found to decrease gradually and changed from positive to neg- ative. The MR effect of the CoxC1-x granular films can be explained by p-n heterojunction theory and interface scattering ef- fect.

Preparation of nanophase M-type ferrite and its laser-attenuated characteristics

By citrate sol-gel auto-combustion method,the nanophase M-type planar hexagonal ferrite is prepared.The transmission electron microscopy(TEM),X-ray diffraction(XRD) and thermal analysis are used to study the grain size,phase composition,microstructure and crystallization process.The results show that the nanophase M-type Sr-ferrite prepared by this method is single,and its grain size is smaller than 100 nm.Moreover,most of the grains present hexagonal sheet shape.Tests are carried out for its attenuation to 1.06 mm laser.It is found that the extinction capability of the nanophase M-type Sr-ferrite smoke is good,and its mass extinction coefficient is 1.628 m2/g.