66 results about "Magnetic relaxation" patented technology

An anti-ferromagnetically coupled, granular-continuous (“AFC-GC”) magnetic recording medium having increased thermal stability, writability, and signal-to-medium noise ratio (“SMNR”), comprising a layer stack including, in sequence from a surface of a non-magnetic substrate: (a) a continuous ferromagnetic stabilizing layer; (b) a non-magnetic spacer layer; and (c) a granular ferromagnetic recording layer; wherein: (i) the continuous ferromagnetic stabilizing and granular ferromagnetic recording layers are anti-ferromagnetically coupled across the non-magnetic spacer layer, the amount of anti-ferromagnetic coupling preselected to ensure magnetic relaxation after writing; (ii) lateral interactions in the granular, ferromagnetic recording layer are substantially completely eliminated or suppressed; and (iii) the exchange coupling strength in the continuous, ferromagnetic stabilizing layer is preselected to be slightly larger than the strength of the anti-ferromagnetic coupling provided by the non-magnetic spacer layer to thereby enhance thermal stability of the recording bits.

An anti-ferromagnetically coupled, granular-continuous (“AFC-GC”) magnetic recording medium having increased thermal stability, writability, and signal-to-medium noise ratio (“SMNR”), comprising a layer stack including, in sequence from a surface of a non-magnetic substrate:(a) a continuous ferromagnetic stabilizing layer;(b) a non-magnetic spacer layer; and(c) a granular ferromagnetic recording layer;wherein:(i) the continuous ferromagnetic stabilizing and granular ferromagnetic recording layers are anti-ferromagnetically coupled across the non-magnetic spacer layer, the amount of anti-ferromagnetic coupling preselected to ensure magnetic relaxation after writing;(ii) lateral interactions in the granular, ferromagnetic recording layer are substantially completely eliminated or suppressed; and(iii) the exchange coupling strength in the continuous, ferromagnetic stabilizing layer is preselected to be slightly larger than the strength of the anti-ferromagnetic coupling provided by the non-magnetic spacer layer to thereby enhance thermal stability of the recording bits.

The invention relates to a weak magnetism detecting instrument based on time-resolved remanence relaxation detection and application thereof. The detecting instrument consists of a detecting unit provided with a sensitive element with high sensitivity therein, a sample bracket, a pulse magnetic field generator, a signal data acquiring and converting system and a computer. The working principle of the detecting instrument is that the superparamagnetic nanomaterial is magnetized via pulse by means of a pulse magnetic field with a steep edge, then a magnetism sensitive element with a high sensitivity is utilized to carry out track analysis on the remanence relaxation generated by the superparamagnetic nanomaterial under the action of the pulse magnetic field, and then a quantitative detection of superparamagnetic nanomaterial is realized. By means of the instrument, biological analysis with high sensitivity can be realized by combining with nano-particles or magnetic beads. The instrument and method of the invention have fast detection speed, low cost, high sensitivity and good stability, and are suitable for fields of biological analysis, disease diagnosis, food security, environment monitoring and the like.

The invention relates to a relaxation time immunosensing analysis method based on magnetic separation. The method comprises the following steps: selecting two magnetic beads (one can be quickly separated and the other cannot be separated) different in saturated magnetization intensity and remarkably different in separation speed in the same magnetic field, so that the magnetic beads can be separated in the magnetic field; coupling the magnetic beads to an antibody used for identifying different sites of the same target object respectively to prepare immunomagnetic beads; producing an immunoreaction of the immunomagnetic beads and a to-be-detected sample; performing magnetic separation on a mixed system, measuring transverse relaxation time for supernatant liquor subjected to magnetic separation, and determining the concentration of biomacromolecules in the to-be-detected sample according to change of the transverse relaxation time. The immunomagnetic beads different in saturated magnetization intensity are different in separation speed in the same magnetic field, the magnetic separation is combined with magnetic relaxation time analysis, the reaction time only needs 30 minutes, and the method can be used for quickly detecting bacteria, viruses and proteins and has a very good application prospect in an aspect of biomarker detection.

A method for measuring the average viscosity of a test fluid uses calibrated magnetic nanoparticles, with certain chosen hydrodynamic diameters and actual lateral dimensions (e.g. diameters), that are mixed into a small volume of the test fluid and a single magnetic relaxation curve measurement to provide data for viscosity determination. The distribution of hydrodynamic particle sizes of an ensemble of magnetic nanoparticles that are magnetically blocked at room temperature can be determined. Modifications of the method can be used to determine the distribution of viscosities in a complex fluid at the sub-microscopic level providing a novel type of viscosity measurement.

A polymer-coated cerium oxide based device and system is disclosed for detecting reactive oxygen species and monitoring chronic inflammation. The device and system encapsulate free therapeutic nanoparticle elements not present in a living body in a prosthetic or implantable unit. Embodiment one is a two-chamber structure with a reactive oxygen species (ROS) scavenging component on one end and at the opposite end is an imaging agent consisting of at least one of a fluorophore capable of fluorescence emission, a chemiluminescent agent, a magnetic relaxation agent and an X-ray contrast agent. Embodiment two is a single chamber device consisting of a multifunctional nanocomposite with a ROS-scavenging nanoparticle constituent (nanoceria) and a multimodal reporting nanoparticle component (i.e. Dex-IO-DiR). The device and system are utilized in treatment of diseases with a pro-inflammatory component, including, but not limited to, Crohn's disease, ulcerative colitis, inflammatory bowel disease, cystic fibrosis, arthritis, and cancer chemotherapy.

The invention belongs to the technical field of nanometer materials, and particularly relates to a zinc oxide-gadolinium-drug composite nanoparticle, and a preparation method and application thereof. The composite nanoparticle comprises a zinc oxide nanocrystal core, a polymer shell, gadolinium (III) ions modified by coordinate bonds and surface-loaded anti-cancer drug molecules, has high stability, luminescence property and magnetic relaxation rate and can be applied to cell and small animal fluorescence imaging, magnetic resonance imaging, mouse tumor treatment and the like. The preparation method includes coating a zinc oxide nanoparticle with a polymer through two copolymerization reactions, coordinating a large quantity of carboxyl groups carried by the polymer with the gadolinium (III) ions to magnetize the nanoparticle, and loading the drug molecules onto the surface of the nanoparticle. A nanoparticle drug loading platform has a good fluorescence-magnetic resonance imaging function, high drug loading rate and high release rate, is low in toxicity and is completely degraded in mouse bodies without residues, thereby having better biosecurity and medication specificity than anti-cancer drugs.

The invention relates to a dysprosium coordination polymer material with solvent molecule magnetic response, which is a dysprosium (III) coordination polymer with unimolecular magnet behaviors. The chemical formula of the dysprosium coordination polymer material is {[Dy(INO)2(NO3)]}, each asymmetric unit contains dysprosium ions which exist in one coordination environment and stores three HINO ligands in connection modes, and dicaryon dysprosium units are further connected through two ligands to form a three-dimensional porous structure. The preparation method of the dysprosium coordination polymer material comprises the following steps of: mixing Dy (NO3)3.6H2O with HINO, and dissolving in a solvent; carrying out heating reaction, and then mixing solids obtained through filtering and washing with acetonitrile; and removing the acetonitrile after the heating reaction. The dysprosium coordination polymer material disclosed by the invention is novel in structure and based on an isonicotinic nitrogen oxide ligand, contains the nanometer-pore three-dimensional coordination polymer, shows the slow magnetic relaxation behavior and can be used as an information storage material; and the preparation method of the dysprosium coordination polymer material has the advantages of simple process, easiness for implementation and high productivity, and is conductive to large-scale popularization and application.

The invention belongs to the technical field of biological detection, and particularly discloses a magnetic relaxation switch based on Fe304@Au and a detection method and detection application thereof. In order to solve the problems of inconvenience and unstable detection results of the technical embodiment of a traditional magnetic relaxation switch, the invention develops a magnetic relaxation switch detection technology with a flower-like Fe304@Au core-shell structure magnetic nanoparticle as a probe. By modifying and identifying biotin molecules on a gold layer on the surface of the nanoparticle, the invention realizes the quick and convenient detection of model protein Avidin, and the detection limit is low to the level of 10nM.

The invention discloses a preparation method of polyacid rare earth ion complex with slow magnetic relaxation behavior. The method comprises the steps of: (1) dissolving alpha-H3PMo12O40.14H2O and LnCl3.6H2O in water according to a certain proportion, heating, stirring and volatilizing the solution to obtain a pale yellow crystal LnPMo12O40.nH2O; (2) reacting the aqueous solution mixture of 4,4-dimethyl-2,2-dipyridyl, glacial acetic acid and hydrogen peroxide for 12-24h under hot water bath, cooling and adding acetone to obtain a pale yellow solid 4,4'-dimethyl-2,2'-dipyridyl-N-N'-dioxide; and (3) performing a slow self-assembled reaction on 4,4'-dimethyl-2,2'-dipyridyl-N-N'-dioxide and the LnPMo12O40.nH2O through a slow diffusion method to obtain the final product is [Ln(bpyno)4][PMo12O40].2H2O. The novel polyacid rare earth complex with slow magnetic relaxation behavior is prepared by the induction of polyacid anions with nanometer sizes, high symmetry and high negative charges; and the preparation method disclosed by the invention is stable, high in yield, good in repeatability and is suitable for actual operations.

The invention belongs to the technical field of radiodiagnostics, and relates to a nanometer graphene oxide-based magnetic resonance imaging contrast agent and a preparation method and an application thereof, in particular to a magnetic resonance imaging MRI contrast agent pGO-Gd which is directly prepared from gadolinium ions (Gd<3+>) and branched polyethylene glycol functionalized nano graphene oxide (pGO). The contrast agent is prepared by directly chelating O and N atoms in a nano carrier material pGO system and the gadolinium ions; chelating agents of DTPA and the like do not need to be additionally introduced; and the contrast agent has high gadolinium ion load rate. The contrast agent can be applied to in vivo angiography, organ imaging, tumor imaging and lymph node imaging through intravenous injection and skin injection; the contrast agent has the advantages of being simple in preparation, high in magnetic relaxation rate, good in dispersity and compatibility, long in in-vivo circulation time, long in imaging time window, wide in application and the like and is beneficial to conversion and popularization.

A polymer-coated cerium oxide based device and system is disclosed for detecting reactive oxygen species and monitoring chronic inflammation. The device and system encapsulate free therapeutic nanoparticle elements not present in a living body in a prosthetic or implantable unit. Embodiment one is a two-chamber structure with a reactive oxygen species (ROS) scavenging component on one end and at the opposite end is an imaging agent consisting of at least one of a fluorophore capable of fluorescence emission, a chemiluminescent agent, a magnetic relaxation agent and an X-ray contrast agent. Embodiment two is a single chamber device consisting of a multifunctional nanocomposite with a ROS-scavenging nanoparticle constituent (nanoceria) and a multimodal reporting nanoparticle component (i.e. Dex-IO-DiR). The device and system are utilized in treatment of diseases with a pro-inflammatory component, including, but not limited to, Crohn's disease, ulcerative colitis, inflammatory bowel disease, cystic fibrosis, arthritis, and cancer chemotherapy.

The invention belongs to the technical field of nuclear magnetic resonance, and particularly discloses a magnetic relaxation switch for detecting glycoprotein. A probe of the magnetic relaxation switch adopts a super-paramagnetic nano particle which uses a ferroferric oxide particle as a core, uses glucan as a shell and has average particle size of no more than 60 nanometers. A method for detecting the glycoprotein by using the magnetic relaxation switch comprises two mixing steps and one detecting step, wherein the mixing steps comprises mixing of agglutinin and mixing of target substance, the agglutinin is concanavalin, and the target substance is a1-acid glycoprotein. The linear concentration range of the detection is 0 to 7.0nmol / L, and the detection limit is 0.40nmol / L and is far lower than the normal concentration of AGP in blood plasma.

The present invention relates to magnetic resonance-based sensors and related methods . More specifically, the invention relates to a sensor based on magnetic resonance for detecting the presence of an analyte in a sample solution. The sensor comprises magnetic nanoparticles linked to a moiety upon which the analyte can reversibly bind, the nanoparticles being confined in a chamber with semipermeable walls which are impermeable to the nanoparticles but permeable to the analyte. Upon binding of the analyte to the nanoparticles, the latter aggregate which can be deteceted by a change in the T2 relaxation time of the sample solution within the chamber (magnetic relaxation switch) . The analyte may be a carbohydrate such as glucose, an antibody, an amino acid, a nucleic acid, an oligonucleotide, a therapeutic agent, a peptide, a protein, etc. The sensor may be used as an assay and may be read out using MRS or MRI, e.g. of well plates for high throughput anaylsis .

The invention discloses a polysaccharide hybrid manganese dioxide nano-particle for magnetic resonance imaging and a preparation method and application thereof. The preparation method includes the steps that polysaccharide with excellent water solubility, biocompatibility and biodegradability is used as a chemical reducing agent and a dispersion stabilizer, the polysaccharide and permanganate are subjected to a chemical reaction in a water solution, and the polysaccharide hybrid manganese dioxide nano-particle is prepared through a single-step method. The adopted natural polysaccharide has excellent water solubility, biocompatibility and biodegradability and further has certain tumor targeting. The prepared polysaccharide hybrid manganese dioxide nano-particle is easily and evenly dispersed in a water system, is safe and low in toxicity, has an obvious magnetic relaxation enhancing effect under the tumor tissue micro-environment condition, is especially suitable for magnetic resonance development imaging of tissue parts of tumors such as glioma, liver cancers and breast cancers, and can be chemically coupled with anti-tumor drugs, and then diagnosis and treatment integration is achieved.

A method for measuring the average viscosity of a test fluid uses calibrated magnetic nanoparticles, with certain chosen hydrodynamic diameters and actual lateral dimensions (e.g. diameters), that are mixed into a small volume of the test fluid and a single magnetic relaxation curve measurement to provide data for viscosity determination. The distribution of hydrodynamic particle sizes of an ensemble of magnetic nanoparticles that are magnetically blocked at room temperature can be determined. Modifications of the method can be used to determine the distribution of viscosities in a complex fluid at the sub-microscopic level providing a novel type of viscosity measurement.

The invention discloses a preparation method of nano Gd-MOFs for magnetic resonance imaging. The preparation method of the nano Gd-MOFs comprises the following steps: (1) dissolving a metal salt, a ligand and a terminating agent in a solvent, and then mixing to obtain a mixed solution; (2) stirring the obtained mixed solution at room temperature, placing in a water bath, carrying out a stirring reaction, then placing in an oven, allowing to stand, centrifuging and washing, and dispersing and preserving by a solvent, to obtain oil-phase dispersed Gd-MOFs; (3) taking a certain amount of the Gd-MOFs obtained in the step (2), centrifuging to remove the solvent, modifying by an ethanol solution containing triethylamine, and finally, dispersing in water to obtain the nano Gd-MOFs for magnetic resonance imaging. Compared with the prior art, the preparation method is simple in preparation process and mild in reaction conditions. The prepared nano Gd-MOFs have the particle size of 45-60 nm, are near spherical, have uniform particle size distribution, and are more suitable for phagocytosis; in an ultra high field intensity of 11.7 T, the transverse relaxation rate r2 is measured to be 96.8 mM<-1>*s<-1>, and the magnetic relaxation rate is high; the disadvantage of high cytotoxicity of the nano Gd-MOFs is overcome; when the concentration of Gd is 0.4 mmol / L or less, the cell close packing T2 weighted imaging effect is obvious.

The invention belongs to the technical field of magnetic relaxation switch detection, in particular to a magnetic relaxation switch based on Fe3O4 at Au and a preparation method thereof. Probes adopted by the magnetic relaxation switch of the invention are flower-shaped magnetic nanometer particles with identification marks decorated on the surfaces, and the flower-shaped magnetic nanometer particles are in Fe3O4 at Au nuclear shell structures, the particle diameter of the probes is ranged from 50 to 70nm, and the relaxation degree R2 of the probes is 9.35 mM<-1>.s<-1>. Through decorating identification molecular biotin on gold layers of the nanometer particle surfaces, the invention realizes the fast, simple and convenient detection of the model protein Avidin, and the detection limit is as low as the level of 10 nM. The invention solves the problems of inconvenient implementation and unstable detection results of the existing magnetic relaxation switch technology.

Quantum magneto-optical sensors involve the field of sensors for quantum-level ultra-trace detection of nuclear magnetic resonance and Raman spectroscopy, specifically including the discovery of the electronic energy of specific protons in the detection object under the states of nuclear magnetic magnetization, nuclear magnetic resonance, nuclear magnetic relaxation and nuclear magnetic demagnetization. The difference in distribution probability of Raman scattered light in azimuth and direction caused by the order transition, and finding and adjusting the optimal magneto-optical angle between excitation light and Raman scattered light will obtain higher collection efficiency of Raman scattered light. The characteristic magnetic spectrum and the characteristic spectrum, according to the quantum correlation, can also find out more information from the quantum correlation. Specifically, the main magnetic field generator, the excitation induction coil, the control subsystem, the laser and the Raman probe constitute the quantum magneto-optical sensor. By adjusting the magneto-optical angle in an off-axis or coaxial way, the Raman spectrum collection efficiency can be improved, and at the same time, the correlation between the characteristic magnetic spectrum and the characteristic spectrum in multiple states can be realized, which provides a calculation basis for further analyzing the content of the detected molecules.

The invention belongs to the field of magnetic resonance imaging and relates to a magnetic relaxation switch-based detection method. According to the method, based on the change of transverse relaxation time T2 of magnetic nanoparticles in dispersion and aggregation states and caused gray scale change in a T2 weight image, specific target molecules are detected through functionalization modification on the surfaces of the magnetic nanoparticles. The method comprises the following steps of: mixing samples to be detected and corresponding functionalized magnetic nanoparticles; placing the mixture on a minitype detection chip; and detecting in a low field magnetic resonance analyzer. Since a minitype multi-sample detection chip with small size is used in the method, required sample quantity is small and multiple samples can be detected in parallel quickly on the low field magnetic resonance analyzer. According to the method, the problem that conventional imaging equipment has high price and large size, is difficult to operate and not suitable for routine lab application and the problem that the low field magnetic resonance analyzer has a small sample chamber and is not suitable for multi-sample parallel detection can be solved.

An array of bonding pads including a set of reactive materials is provided on a first substrate. The set of reactive materials is selected to be capable of ignition by magnetic heating induced by time-dependent magnetic field. The magnetic heating can be eddy current heating, hysteresis heating, and / or heating by magnetic relaxation processes. An array of solder balls on a second substrate is brought to contact with the array of bonding pads. A reaction is initiated in the set of magnetic materials by an applied magnetic field. Rapid release of heat during a resulting reaction of the set of reactive materials to form a reacted material melts the solder balls and provides boding between the first substrate and the second substrate. Since the magnetic heating can be localized, the heating and warpage of the substrate can be minimized during the bonding process.

The invention discloses a magnetic signal probe of a magnetic relaxation time immunosensor. The probe comprises a Gd < 3 + > chelate, polylysine and a superparamagnetic nano-particle of an antibody which are coupled. By coupling polylysine and an antibody to the surfaces of superparamagnetic nano-particles,the antibody-superparamagnetic nanoparticle-polylysine conjugate with the multi-dimensionalspace reticular dendritic structure is obtained; then, succinimide-tetraazacyclododecane tetraacetic acid with chelating performance is coupled to the surface of polylysine, and paramagnetic Gd < 3 +> ions are added; gd < 3 + > is captured through DOTA, and finally, a large number of Gd < 3 + > ions are chelated on the surfaces of the superparamagnetic nano-particles, so that the magnetic relaxation time immunosensing magnetic signal probe with multiple signal amplification is obtained. According to the invention, magnetic separation and magnetic sensing integrated nano magnetic particles andparamagnetic Gd < 3 + > ions are controllably assembled into the multifunctional nano magnetic probe for the first time, so that multiple amplification of sensing signals is realized, and the sensitivity and detection speed of the sensor are greatly improved.

The invention discloses a method for changing the number and state of nano magnetic particles based on a biological orthogonal reaction for detecting pesticide residues. According to the method, the number and the aggregation state of the nano magnetic particles are changed simultaneously on the basis of the cascade biological orthogonal reaction of diphenyl cyclooctyne and azide, controllable adjustment of the number and the state of the magnetic nano particles is realized, and magnetic signal cascade amplification is performed by organic combination of diphenyl cyclooctyne and azide, so thatthe accuracy and the sensitivity of pesticide residue detection are improved.

Described here are systems and methods for producing high-resolution three-dimensional (“3D”) relaxation parameter maps by calibrating high-resolution 3D magnetic resonance images. As one example, high-resolution longitudinal relaxation time (“T1”) maps can be generated based on images acquired using a T1-weighted pulse sequence, and as another example high-resolution transverse relaxation time (“T2”) maps can be generated based on images acquired using a T2-weighted pulse sequence. The high-resolution images can be calibrated, for example, using a lower resolution single slice relaxation parameter map. The methods described here utilize high-resolution 3D scans and low-resolution relaxation parameter maps that are commonly available on MRI systems. The calibration is a post-processing step used to create the high-resolution 3D relaxation parameter maps from these two types of scans.

The present invention can provide a method of determining the presence, location, quantity, or a combination thereof, of a biological substance, comprising: (a) exposing a sample to a plurality of targeted nanoparticles, where each targeted nanoparticle comprises a paramagnetic nanoparticle conjugated with one or more targeting agents that preferentially bind with the biological substance, under conditions that facilitate binding of the targeting agent to at least one of the one or more biological substances; (b) subjecting the sample to a magnetic field of sufficient strength to induce magnetization of the nanoparticles; (c) measuring a magnetic field of the sample after decreasing the magnetic field applied in step b below a threshold; (d) determining the presence, location, quantity, or a combination thereof, of the one or more biologic substances from the magnetic field measured in step (c).

The invention provides a triazinyl tricarboxylic acid heavy rare earth complex. The specific chemical formula is [Ln2(TCT)2(H2O)6].6H2O, wherein Ln is selected from Tb or Dy or Ho or Er or Tm or Yb or Lu, TCT is 2,4,6-tri(carboxymethyl sulfydryl)-1,3,5-triazine negative ion, and meanwhile the invention provides a preparing method and a characterization method of the triazinyl tricarboxylic acid heavy rare earth complex. Synthesis raw materials are easy to obtain, the synthesis method is simple, a reaction does not be carried out under the high-temperature high-pressure hydrothermal or solvothermal condition, the cost is low, and the yield is high; the synthesized triazinyl tricarboxylic acid heavy rare earth complex is poor in water solubility, and is also difficultly dissolved in a common organic solvent, and secondary pollution to the environment is prevented; the prepared triazinyl tricarboxylic acid heavy rare earth complex shows the ligand-sensitized rare-earth-ion-lighting and the field-induced slow magnetic relaxation behavior, and can serve as applications of light and magnetism function materials.

The present invention provides methods and apparatuses for detecting, measuring, or locating cells or substances present in even very low concentrations in vivo in subjects, using targeted magnetic nanoparticles and special magnetic systems. The magnetic systems can comprise magnetizing subsystems and sensors subsystems, including as examples SQUID sensors and atomic magnetometers. The magnetic systems can detect, measure, or location particles bound by antibodies to cells or substances of predetermined types. Example magnetic systems are capable of detecting sub-nanogram amounts of these nanoparticles.

The invention discloses a magnetic cobalt (II) complex based on a 4,4'-bipyridine-itaconic acid derivative ligand and a preparation method of the magnetic cobalt (II) complex. The molecular formula ofthe magnetic cobalt (II) complex is [[Co(HL)2(H2O)2].2NO3]n, wherein HL represents the 4,4'-bipyridine-itaconic acid derivative ligand with one hydrogen atom removed from carboxylic acid, a single-crystal structure has a one-dimensional chain structure, and an asymmetric construction unit of the single-crystal structure contains half cobalt (II) ion, one 4,4'-bipyridine-itaconic acid derivative ligand, one end coordination water molecule and one free nitrate anion; pyridine nitrogen in 4,4'-bipyridineis subjected to an electrophilic addition reaction with double bonds in itaconic acid, a semi-rigid carboxylate ligand containing N(+)-C bonds is synthesized, and the ligand and the cobalt (II) ion are subjected to an in-situ coordination reaction, and the cobalt (II) complex is synthesized;the cobalt (II) complex has slow magnetic relaxation phenomenon at the low temperature and serves as a molecule-based magnetic material to be applied to the fields of information storage, quantum computation and the like.