A simple method for purification of genomic DNA from whole blood using Fe_3O_4/Au composite particles as a carrier

Objective： To establish a method of genomic DNA extraction from whole blood using Fe3O4/Au composite particles as a carrier. Methods： Two crucial conditions （sodium chloride concentration and amount of the magnetic particles） were optimized and 8 different human whole blood samples were used to purify genomic DNA under the optimal condition. Then agarose gel electrophoresis and polymerase cbain reaction （PCR） were performed. Results： The optimal binding condition was 1.5 mol/L NaC1/10% PEG, and the optimal amount of Fe3O4/Au composite particles was 600μg. The yields of the genomic DNA from 100μl of different whole blood samples were 2-5 μg, and the ratio of A260/A280 was in the range of 1.70-1.90. The size of genomic DNA was about 23 kb and the PCR was valid. Conclusion： The purification system using Fe3O4/Au composite microparticles has advantages in high yield, high purity, ease of operating, time saving and avoiding centrifugation. The purified sample was found to function satisfactorily in PCR amplification.

Novel Magnetorheological Suspensions Based on Co-Phthalocyanine/Fe Nanocomposite Particles

A novel magnetorheological (MR) suspension was based on methyl silicone oil and cobalt-phthalocyanine (Co-Pc)/Fe nanocomposite particles, which were synthesized by thermally decomposing liquid carbonyl Fe in the solution of Co-Pc in N, N-dimethyl formamide. The nanocomposite particles were fully characterized by XRD, SEM and HREM, and the thermal, magnetic and MR properties of nanocomposite particles were measured. Such factors as weight percent of particles (w), magnetic field strength (H), temperature (T) and shear rate (gamma) etc influencing on MR properties were investigated. The results indicated that Co-Pc/Fe nanocomposite with density of 3.66 g/cm(3) was almost micro-sized regular spheroids consisting of tens of Co-Pc coated alpha -Fe nanoparticles in inner and Co-Pc layers on surface of the spheroids. They showed good characteristics of anti-oxidation and soft magnetic. Increment of w increased field-induced shear stress (Delta tau) and zero-field viscosity (eta (0)) of MR suspensions monotonously, and improved anti-settlement stability, but eta (0) increased more markedly than Delta tau with increasing w. Delta tau was basically independent on T and gamma while increased obviously with increasing H. With increasing T, response time of the MR suspension to external magnetic field seemed to decrease. As a result, MR suspensions with satisfactory stability and rapid, completely reversible and significant MR effect can be obtained from Co-Pc/Fe nanocomposite particles.

Catalytic dechlorination of chlorinated methanes by nanoscale Pd/Fe bimetallic particles

This paper examined the potential of using laboratory-synthesized nanoscale Pd/Fe bimetallic particles to dechlorinate chlorinated methanes, including dichloromethane (DCM), trichloromethane (CF) and tetrachloromethane (CT). Nanoscale Pd/Fe bimetallic particles were characterized in terms of surface area, morphology, size and structure. The parameters affecting the dechlorination efficiency were studied through batch experiments. Effects of Pd content, Pd/Fe addition, and the initial pH value of reaction system on the dechlorination efficiency of chlorinated methanes were determined systematically. Results show that nanoscale Pd/Fe bimetallic particles play a prominent role in the dechlorination of chlorinated methanes. The change of pH value and ferrous ion concentration during dechlorination reaction were also investigated in this study. It is found that the dechlorination efficiency of chlorinated methanes is in the order of CT>CF>DCM.

Preparation of Fe_3O_4/PS Magnetic Particles by Dispersion Polymerization

Fe_3O_4/PS magnetic particles with core/shell structure has been prepared in the presence of Fe3O4 magnetic fluid in ethanol/water mixture.Magnetic particles with diameter size range from 5. 54 t0 187. 32 μm were obtained by different reaction conditions.Some parameters such as ethanol, PEG and monomer which affect particle size diameter and size distribution are discussed briefly in this paper.

均分散针状α－Fe_(2)O_(3)的制备

均分散针状α－Ｆｅ_２Ｏ_３的制备魏雨，郑学忠，刘晓林，邵素霞，鹿平（河北师范大学化学系石家庄０５００１６）（河北师范大学分析测试中心石家庄）关键词α－Ｆｅ_２Ｏ_３，Ｆｅ（ＯＨ）_３，针形粒子均分散α－Ｆｅ_２Ｏ_３的合成方法有沉化法［１］、强迫水解法［?..

Dechlorination of disinfection by-product monochloroacetic acid in drinking water by nanoscale palladized iron bimetallic particle

Nanoscale palladized iron(Pd/Fe)bimetallic particles were prepared by reductive deposition method.The particles were characterized by X-ray diffraction(XRD),X-ray fluorescence(XRF),scanning electron microscope(SEM),transmission electron microscope(TEM),and Brunauer-Emmett-Teller-nitrogen(BET-N_2)method.Data obtained from those methods indicated that nanoscale Pd/Fe bimetallic particles containedα-Fe^0.Detected Pd to Fe ratio by weight(Pd/Fe ratio)was close to theoretical value. Spherical granules with diame...

Research on Surface Peeling in Cu-Fe-P Alloy

Surface peeling of Cu-Fe-P lead frame alloy was analyzed using plane strain model and elastoplastic finite element method. Based on the characterization of microstructure at surface peeling in finish rolled Cu-Fe-P lead frame alloy, the stress and strain distributions of the interface between Cu matrix and Fe particle are studied. Results indicate that the equivalent strain mismatch 6.9% between Cu matrix and Fe particle and the intense stress concentration at the interface have influence on surface peeling generation. The crack is prone to the electrical conductivity decreasing of Cu-Fe-P alloy and surface peeling on finish rolling.

Electrodeposition of Ni-Co-Fe_2O_3 composite coatings

Ni-Co-Fe2O3 composite coatings were electrodeposited using cetyltrimethylammonium bromide(CTAB)-modified Watt's nickel bath with Fe2O3 particles dispersed in it.The effects of the plating parameters on the chemical composition,structural and morphological characteristics of the electrodeposited Ni-Co-Fe2O3 composite coatings were investigated by energy dispersive X-ray(EDS) spectroscopy,X-ray diffractometry(XRD) and scanning electron microscopy(SEM).The results reveal that Fe2O3 particles can be codeposited in the Ni-Co matrix.The codeposition of Fe2O3 particles with Ni-Co is favoured at high Fe2O3 particle concentration and medium stirring,and the deposition of Co is favoured at high concentration of CTAB.Moreover,the study of the textural perfection of the deposits reveals that the presence of particles leads to the worsening of the quality of the observed <220> preferred orientation.Composites with high concentration of embedded particles exhibit a preferred crystal orientation of <111>.The more the embedded Fe2O3 particles in the metallic matrix,the smaller the sizes of the crystallite for the composite deposits.

Oxidative-damage effect of Fe3O4 nanoparticles on mouse hepatic and brain cells in vivo

To assess the biological safety of Fe3O4 nanoparticles （NPs）, the oxidative-damage effect of these NPs was studied. Twenty-five Kunming mice were exposed to Fe3O4 NPs by intraperitoneai injection daily for 1 week at doses of 0, 10, 20, and 40 mg.kg1. Five Kunming mice were also injected with 40 mg.kg 1 ordinary Fe3O4 particles under the same physiological conditions. Biomarkers of reactive oxygen species （ROS）, glutathione （GSH）, and malondialdehyde （MDA） in the hepatic and brain tissues were detected. Results showed that no significant difference in oxidative damage existed at concentrations lower than 10 mg.kg i for NPs compared with the control group. Fe3O4 NP concentration had obvious dose-effect relationships （P〈 0.05 or P 〈 0.01） with ROS level, GSH content, and MDA content in mouse hepatic and brain tissues at〉20 mg.kg 1 concentrations. To some extent, ordinary Fe3O4 particles with 40mg.kg -1 concentration also affected hepatic and brain tissues in mice. The biological effect was similar to Fe3O4 NPs at 10 mg. kg-1 concentration. Thus, Fe3O4 NPs had significant damage effects on the antioxidant defense system in the hepatic and brain tissues of mice, whereas ordinary Fe3O4 had less influence than Fe3O4 NPs at the same concentration.

Preparation and characterization of Pd/Fe bimetallic nanoparticles immobilized on Al_2O_3/PVDF membrane:Parameter optimization and dechlorination of dichloroacetic acid

Using a liquid-solid phase inversion method, a hybrid matrix poly（vinylidene fluoride）（PVDF） membrane was prepared with alumina（Al2O3） nanoparticle addition. Pd/Fe nanoparticles（NPs） were successfully immobilized on the Al2O3/PVDF membrane, which was characterized by Scanning Electron Microscopy（SEM） and Transmission Electron Microscopy（TEM）. The micrographs showed that the Pd/Fe NPs were dispersed homogeneously. Several important experimental parameters were optimized, including the mechanical properties, contact angle and surface area of Al2O3/PVDF composite membranes with different Al2O3 contents. At the same time, the ferrous ion concentration and the effect of hydrophilization were studied. The results showed that the modified Al2O3/PVDF membrane functioned well as a support. The Al2O3/PVDF membrane with immobilized Pd/Fe NPs exhibited high efficiency in terms of dichloroacetic acid（DCAA） dechlorination. Additionally, a reaction pathway for DCAA dechlorination by Pd/Fe NPs immobilized on the Al2O3/PVDF membrane system was proposed.

Preparation and characterization of silicone-oil-based γ-Fe2O3 magnetic fluid

In this study, silicone-oil-based γ-Fe2O3 mag- netic fluid was successfully prepared by thermal oxidizing of Fe3O4 magnetic nanoparticles, which were prepared by chemical co-precipitation with FeSO4-7H2O and FeCl3- 6H2O, and their surface was modified by oleate ligands. Silicone oil was used as carrier liquid and oleic acid was as surfactant for preparing γ-Fe2O3 magnetic fluid. It is found that the Fe3O4 nanoparticles surrounded by oleate ligands are not damaged during the thermal oxidizing. The shape of γ-Fe2O3 magnetic nanoparticles prepared is similar to spherical, and their mean size is about 10-20 nm, which has nothing obvious difference compared with Fe3O4. Thesaturation magnetization of γ-Fe2O3 magnetic fluid pre-pared is 14.25 A.me.kg-1 and that of γ-Fe2O3 nanoparti-cles is 57.56 A.m2.kg-1. The needle of γ-Fe2O3 magneticfluid is much bigger than that of Fe3O4 magnetic fluidunder the same magnetic field, which shows better mag-netic properties.