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内容記述 |
Dynamic nuclear polarization (DNP) is a quantum technology that temporarily increases the sensitivity of nuclear magnetic resonance (NMR) over 10,000-fold (Figure). Given the biomolecules (MW: <~200) labeled with NMR-positive nuclei (e.g. 13C, 15N; Spin-1/2 isotopes) and mixed with a radical resource for an appropriate manner, irradiation of microwave for the suitable period with the resonance frequency under the magnetic field realizes the electron spin polarization and subsequent polarization transfer to the labeled nuclei under the appropriate physicochemical conditions. This aligns most of the nuclear spins toward one side of the direction (lower energy level) as the magnetic field (B0) on the polarizer magnet (hyperpolarized state), resulting in the enhancement of following NMR signals from the biomolecules on MRI/NMR apparatus until the polarization goes back to the thermal equilibrium of the original steady state (several minutes). Thus, by manipulating the spin state of nuclides by DNP, hypersensitive MRI/NMR measurement with time-resolving repeated single scans can be feasible, which allows direct monitoring of the molecular metabolism and otherwise cannot be accomplished on the conventional measurement with “low sensitivity”. This poster represents the concise basis of dissolution DNP (triplet DNP/cryogenic DNP). In addition, research and development (R&D) of each criterion aiding hypersensitive MRI/NMR for biomedical applications will also be shown. These include i) the materials development, ii) bioreactor construction for direct monitoring of cell metabolism, iii) information science for processing the hypersensitive MRI/NMR data, iv) cancer research for early diagnosis of malignancy or therapeutic response, v) brain research focusing on the sugar metabolism, and vi) clinical research directed for the human use. Our current R&D of hypersensitive MRI/NMR will be discussed. |
