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Results for “Ferrosoferric Oxide”

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At least 19 recordsLinked to original sources
PubMed2006

Magnetization influence on the performance of ferrosoferric oxide: polyacrylonitrile membranes in ultrafiltration of pig blood solution.

Three kinds of membranes were prepared from suspensions containing polyacrylonitrile, dimethyl sulfoxide, polyethylene glycol and different amount of Fe3O4 by the phase inversion process. The rejection rate and the flux of membrane were investigated in the filtration of pig blood solution. SEM also studied the morphologies of fouled membranes. The permeate flux and the rejection rate decline fast in the initial several minutes and then change slowly. The magnetized membrane has a higher flux and a relative flux than the corresponding non-magnetized membrane. And the magnetized membrane containing about 3 wt% Fe3O4 has a prominent anti-fouling performance with above 52% relative flux. The results indicate that the magnetized ferrosoferric oxide-polyacrylonitrile membranes are promising in the recovery of blood proteins in the slaughterhouse effluents. In addition, the hydraulic resistance model explained results and the fouling mechanism was also given.

Acrylic Resins↗
PubMed1999

In vitro toxicity of gallium arsenide in alveolar macrophages evaluated by magnetometry, cytochemistry and morphology.

Gallium arsenide (GaAs), a chemical compound of gallium and arsenic, causes various toxic effects including pulmonary diseases in animals. Since the toxicity is not completely investigated, GaAs has been used in workplaces as the material of various semiconductor products. The present study was conducted to clarify the toxicity of GaAs particles in the alveolar macrophages of hamsters using magnetometry, enzyme release assays and morphological examinations. Alveolar macrophages obtained from hamsters by tracheobronchial lavage and adhered to the disks in the bottom of wells were exposed to ferrosoferric oxide and GaAs particles. Ferrosoferric oxide particles were magnetized externally and the remanent magnetic field was measured. Relaxation, a fast decline of the remanent magnetic fields radiated from the alveolar macrophages, was delayed and decay constants were decreased dose-dependently due to exposure to GaAs. Because the relaxation is thought to be associated with cytoskeleton, the exposure of GaAs may have impaired the motor function of them. Enzyme release assay and morphological findings indicated the damage to the macrophages. Thus the cytotoxicity causes cytostructural changes and cell death. According to DNA electrophoresis and the TUNEL method, necrotic changes occur more frequently than apoptotic changes.

Animals↗
PubMed2002

In vitro toxicity of indium arsenide to alveolar macrophages evaluated by magnetometry, cytochemistry and morphological analysis.

The present study was conducted to clarify the toxicity of Indium arsenide (InAs) particles to alveolar macrophages of hamsters by cytomagnetometry, enzyme release assays and morphological examinations. One million alveolar macrophages obtained from hamsters were exposed to 60 microg of ferrosoferric oxide and 2, 4, 10 and 20 microg of InAs particles. Relaxation, which is the rapid decline of strength of the remanent magnetic fields radiating from the alveolar macrophages, was insignificantly delayed and decay constants were not changed due to exposure to such doses of InAs. Because the relaxation is thought to be associated with the cytoskeleton, the exposure to InAs may not have impaired their motor function. An LDH release assay and morphological findings indicate slight damage to macrophages. DNA electrophoresis and the TUNEL method revealed neither necrotic changes nor apoptotic changes. Thus, InAs particles at such doses hardly cause cytostructural changes and cell death.

Animals↗
PubMed2006

Synthesis and characterization of highly ordered cobalt-magnetite nanocable arrays.

Magnetically tunable, high-density arrays of coaxial nanocables within anodic aluminum oxide (AAO) membranes have been synthesized. The nanocables consist of magnetite nanowires surrounded by cobalt nanotube sheaths and cobalt nanowires surrounded by magnetite nanotube sheaths. These materials are a combination of separate hard (Co) and soft (Fe3O4) magnetic materials in a single nanocable structure. The combination of two or more magnetic materials in such a radial structure is seen as a very powerful tool for the future fabrication of magnetoresistive, spin-valve and ultrafast spin-injection devices with nonplanar geometries. The nanocable arrays were prepared using a supercritical-fluid inclusion process, whereby the nanotube was first deposited onto the pore walls of the nanoporous membranes and subsequently filled with core material to form coaxial nanocables. In essence, this paper describes a technique for placing novel magnetic technologies into well-defined building blocks that may ultimately lead to new multifunctional devices, such as spin valves and high-density magnetic storage devices.

Aluminum Oxide↗
PubMed2005

Stability of mixtures of charged silica, silica-alumina, and magnetite colloids.

We report experiments on the stability of aqueous mixtures of charged colloidal magnetite and charged silica and silica covered with alumina particles of similar size. First, positively charged magnetite dispersions were mixed with negatively charged silica dispersions at pH 4, at different volume ratios and low colloid volume fractions, producing mixtures which were stable over a period of weeks despite the expected electrostatic attraction between the oppositely charged particles. When magnetite particles were mixed with positively charged silica covered with alumina at pH 4 under exactly the same conditions, some of the systems separated to form a magnetite sediment. When the volume fraction of the initial dispersions was increased, the behavior of the mixtures was the opposite: positive magnetite/negative silica mixtures were unstable at intermediate volume ratios. The unexpected behavior of the mixtures was investigated by means of electrophoretic mobility, initial susceptibility, and dynamic light scattering measurements as well as sedimentation experiments.

Aluminum Oxide↗
PubMed1990

Microsomal lipid peroxidation and oxy-radicals formation are induced by insoluble iron-containing minerals.

Lipid peroxidation, measured by malondialdehyde formation is induced in rat liver microsomes by insoluble iron-containing minerals (pyrite, magnetite, nemalite and an iron ore, minette de Lorraine) which are generally found either in iron mines or as contaminants of asbestos fibers. In spin-trapping studies using DMPO as a spin trap those minerals are also found to catalyze the oxidation of formate to carboxylate radicals by oxygen, via the formation of hydroxyl radicals. The two processes are mainly due to the presence of redox active iron at the surface of the solid particles and thus are greatly inhibited by desferrioxamine, a strong iron chelator. However, these reactions are not correlated.

Animals↗
PubMed2006

The adsorption and reaction of a titanate coupling reagent on the surfaces of different nanoparticles in supercritical CO2.

The adsorption and reaction in supercritical CO2 of the titanate coupling reagent NDZ-201 on the surfaces of seven metal oxide particles, SiO2, Al2O3, ZrO2, TiO2 (anatase), TiO2 (rutile), Fe2O3, and Fe3O4, was investigated. FTIR and TG analysis indicated that the adsorption and reaction were different on different particle surfaces. On SiO2 and Al2O3 particles, there was a chemical reaction of the titanate coupling reagent on the surfaces. On the surfaces of ZrO2 and TiO2 (anatase) particles, there were two kinds of adsorption, weak and strong adsorption. On the surfaces of TiO2 (rutile), Fe2O3, and Fe3O4 particles, there was only weak adsorption. The acidity or basicity of the OH groups on the particle surface was the key factor that determined if a surface reaction occurred. When the OH groups were acidic, the titanate coupling reagent reacted with these, but otherwise, there was no reaction. The surface density of OH groups on the original particles and the amount of titanate coupling reagent adsorbed and reacted were estimated from TG analysis. The reactivity of the surface OH groups of Al2O3 particles was higher than that of the SiO2 particles.

Adsorption↗
PubMedDate not supplied

An evaluation of the contributions of diffusion and exchange in relaxation enhancement by MRI contrast agents.

Magnetic compounds are known to enhance water proton relaxation, either by diffusion or by proton exchange. An experimental procedure to distinguish both mechanisms is proposed and validated by relaxation measurements made in water-methanol solutions of Dy(3+), Ni(2+), Gd(3+), Tempo, and AMI-25. The test discriminates according to the character of the transverse relaxation in water-methanol solutions: a mono-exponential decay corresponds to diffusion, while a bi-exponential decay indicates the contribution of a proton exchange. The study of ferritin and akaganeite particle solutions confirms the occurrence of a proton exchange between protons belonging to hydroxyl groups of the particle surface and free water protons.

Contrast Media↗
PubMed1992

MRI susceptometry: image-based measurement of absolute susceptibility of MR contrast agents and human blood.

We present a novel NMR imaging technique that allows absolute determination of the magnetic susceptibility constant, chi, of a solution. By comparing the phase difference of MR images produced with an instant (echo planar) "offset" spin-echo sequence, we obtain a direct measure of the magnetic field perturbations caused by the solution. We demonstrate this method with Gd(DTPA), Dy(DTPA), human red blood cells, and superparamagnetic iron oxide particles.

Contrast Media↗