Abstract: Provided are a polarizing agent that can selectively enhance NMR signals by the DNP-NMR method even in a reducing environment, and a method for selectively enhancing NMR signals. The present invention is a polarizing agent for use in the DNP-NMR method, the polarizing agent comprising nanodiamond particles, and the nanodiamond particles having a surface modified with a functional group capable of covalently binding to or interacting with proteins. The polarizing agent of the present invention can selectively enhance NMR signals by the DNP-NMR method even in a reducing environment.

Abstract: An NMR apparatus includes a depressurizing device for depressurizing an NMR probe, a gas supply device for supplying gas into the NMR probe to thereby pressurize the NMR probe, and a control device. The control device alternately repeats depressurization of the NMR probe, using the depressurizing device, and pressurization of the NMR probe, using the gas supply device. This replaces the gas in the NMR probe.

Abstract: An NMR apparatus includes a depressurizing device for depressurizing an NMR probe, a gas supply device for supplying gas into the NMR probe to thereby pressurize the NMR probe, and a control device. The control device alternately repeats depressurization of the NMR probe, using the depressurizing device, and pressurization of the NMR probe, using the gas supply device. This replaces the gas in the NMR probe.

Abstract: A container has a sample installation unit and an NMR circuit therein, and is connected to a bearing gas supply path and a drive gas supply path for supplying gas to the inside of that container. This container is also connected to an exhaust path that exhausts the gas from the inside of the container. The exhaust path has a pressure control valve as an adjustment mechanism for adjusting the pressure in the container.

Abstract: Attenuation of microwaves is reduced or prevented when vacuum windows are provided in microwave waveguides of a DNP-NMR probe. A DNP-NMR probe has an inner container and an outer container. The inner container has therein a sample tube containing a sample to which radicals are added. The outer container keeps a space between the outer container and the inner container in the outer container in a vacuum state. The outer container has an outer container waveguide that has a vacuum window at an inner end portion and guides microwaves. The inner container has a vacuum window facing the vacuum window of the outer container waveguide through vacuum, and guides microwaves transmitted from the outer container waveguide to the sample. The window-to-window distance between the vacuum window of the outer container and the vacuum window of the inner container is adjusted by means of adjustment bolts.

Abstract: A rotor contains a sample. A turbine cap is fitted into an opening of one end of the rotor, and a bottom cap is fitted into an opening of the other end of the rotor. A recess portion is formed in the turbine cap, and a recess portion is formed in the bottom cap. Insert members having a negative linear expansion coefficient are disposed in the recess portions.

Abstract: Attenuation of microwaves is reduced or prevented when vacuum windows are provided in microwave waveguides of a DNP-NMR probe. A DNP-NMR probe has an inner container and an outer container. The inner container has therein a sample tube containing a sample to which radicals are added. The outer container keeps a space between the outer container and the inner container in the outer container in a vacuum state. The outer container has an outer container waveguide that has a vacuum window at an inner end portion and guides microwaves. The inner container has a vacuum window facing the vacuum window of the outer container waveguide through vacuum, and guides microwaves transmitted from the outer container waveguide to the sample. The window-to-window distance between the vacuum window of the outer container and the vacuum window of the inner container is adjusted by means of adjustment bolts.

Abstract: A container has a sample installation unit and an NMR circuit therein, and is connected to a bearing gas supply path and a drive gas supply path for supplying gas to the inside of that container. This container is also connected to an exhaust path that exhausts the gas from the inside of the container. The exhaust path has a pressure control valve as an adjustment mechanism for adjusting the pressure in the container.

Abstract: A rotor contains a sample. A turbine cap is fitted into an opening of one end of the rotor, and a bottom cap is fitted into an opening of the other end of the rotor. A recess portion is formed in the turbine cap, and a recess portion is formed in the bottom cap. Insert members having a negative linear expansion coefficient are disposed in the recess portions.

Abstract: A sample rotor is placed in a sample chamber inside an inner container. An air bearing type rotation mechanism blows a refrigerant gas (composed of a bearing gas and a driving gas) onto the sample rotor, to rotate the sample rotor and simultaneously cool the same. The refrigerant gas discharged from the air bearing type rotation mechanism is filled in an internal space (such as the sample chamber and a detection circuit chamber) of the inner container. An upper airtight chamber is formed between an outer container and the inner container. A lower airtight chamber is formed below a sealing bulkhead within a bottom unit. The upper and lower airtight chambers are in vacuum states to thereby function as vacuum insulation spaces for the internal space of the inner container.

Abstract: A sample rotor is placed in a sample chamber inside an inner container. An air bearing type rotation mechanism blows a refrigerant gas (composed of a bearing gas and a driving gas) onto the sample rotor, to rotate the sample rotor and simultaneously cool the same. The refrigerant gas discharged from the air bearing type rotation mechanism is filled in an internal space (such as the sample chamber and a detection circuit chamber) of the inner container. An upper airtight chamber is formed between an outer container and the inner container. A lower airtight chamber is formed below a sealing bulkhead within a bottom unit. The upper and lower airtight chambers are in vacuum states to thereby function as vacuum insulation spaces for the internal space of the inner container.

Abstract: The present invention relates to the field of organic chemistry and in particular to organic free radicals used as polarizing agents in the technique of Dynamic Nuclear Polarization (DNP), which involves transferring the polarization of electron spins to the nuclei of a compound whose Nuclear Magnetic Resonance (NMR) is being observed. It concerns Dinitroxide-type Biradical polarizing agents characterized by a rigid linkage between the aminoxyl groups of said nitroxide units. This particular structure enables, at low temperatures and high fields, optimal transfer of polarization and optimal enhancement of NMR/MAS signals of the polarized nuclei of the compound studied.

Abstract: The present invention relates to the field of organic chemistry and in particular to organic free radicals used as polarizing agents in the technique of Dynamic Nuclear Polarization (DNP), which involves transferring the polarization of electron spins to the nuclei of a compound whose Nuclear Magnetic Resonance (NMR) is being observed. It concerns Dinitroxide-type Biradical polarizing agents characterized by a rigid linkage between the aminoxyl groups of said nitroxide units. This particular structure enables, at low temperatures and high fields, optimal transfer of polarization and optimal enhancement of NMR/MAS signals of the polarized nuclei of the compound studied.

Abstract: The present invention relates to the field of organic chemistry and in particular to organic free radicals used as polarizing agents in the technique of Dynamic Nuclear Polarization (DNP), which involves transferring the polarization of electron spins to the nuclei of a compound whose Nuclear Magnetic Resonance (NMR) is being observed. It concerns dinitroxide-type biradical polarizing agents characterized by a rigid linkage between the nitroxide units that enables optimal orientation and distance to be maintained between the aminoxyl groups of said nitroxide units. This particular structure enables, at low temperatures and high fields, optimal transfer of polarization and optimal enhancement of NMR/MAS signals of the polarized nuclei of the compound studied.

Abstract: The present invention relates to the field of organic chemistry and in particular to organic free radicals used as polarizing agents in the technique of Dynamic Nuclear Polarization (DNP), which involves transferring the polarization of electron spins to the nuclei of a compound whose Nuclear Magnetic Resonance (NMR) is being observed. It concerns dinitroxide-type biradical polarizing agents characterized by a rigid linkage between the nitroxide units that enables optimal orientation and distance to be maintained between the aminoxyl groups of said nitroxide units. This particular structure enables, at low temperatures and high fields, optimal transfer of polarization and optimal enhancement of NMR/MAS signals of the polarized nuclei of the compound studied.