Spin conversion of hydrogen using supported iron catalysts at cryogenic temperature

Das, Taraknath; Kweon, Soon-Cheol; Nah, In Wook; Karng, Sarng Woo; Choi, Jeong-Gil; Oh, In‐Hwan

doi:10.1016/j.cryogenics.2015.03.003

Cited by 15 publications

(19 citation statements)

References 75 publications

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“…[16, 18] The spin-conversion catalyst is typically made of iron oxides [19] or other metal oxides [20] and is stored in a metal tube, [21] aluminum cylinder [16b, 22] or a glass-trap. The spin conversion catalyst should be completely immersed in the cooling liquid/jacket to avoid back conversion at room temperature.…”

Section: How It Work: Principles Of Parahydrogen-based Polarizationmentioning

confidence: 99%

“…[16] rtH 2 is converted into about 51 %pH 2 by flowing the gas through as pin-conversion catalyst at 77 K. [17] Alternatively, rtH 2 can be passed through ac atalyst-containing chamber cryogenically chilled to about 22 Kt oa chieve > 95 % pH 2 . [16,18] Thes pin-conversion catalyst is typically made of iron oxides [19] or other metal oxides [20] and is stored in ametal tube, [21] aluminum cylinder, [16b, 22] or ag lass-trap.T he spinconversion catalyst should be completely immersed in the cooling liquid/jacket to avoid back conversion at room temperature.N ote that ah igh pH 2 enrichment is favorable because the level of hyperpolarization directly depends on it.…”

Section: Production Of Parahydrogenmentioning

confidence: 99%

“…1 Hpolarization of above 50 %has been achieved. [48] However,i ft he goal is to efficiently hyperpolarize heteronuclei such as 15 N, 13 C, or 19 F, then (w H Àw S )i s dominated by the difference of the gyromagnetic ratios of the nuclei and we require sub-mTfields to fulfill Eq. (7).…”

Section: Converting the Ph 2 Spin Order Into Hyperpolarizationmentioning

confidence: 99%

“…Efficient polarization transfer to 1 H( > 50 %), [48]1 5 N (> 34 %), [39f,50b] 13 C( > 15 %), [49a] as well as to 19 F, [49b] 119 Sn, and 29 Si [93] has been shown in methanolic solutions.…”

Section: Homogeneous Sabre Catalysismentioning

confidence: 99%

“…Considerable research is focused on the hyperpolarization of heteronuclei. Fore xample,d espite its relatively short T 1 value (i.e.onthe order of few seconds), 19 Fexhibits attractive properties such as ahigh MR sensitivity and optimal contrast (a high signal to noise ratio similar to that of protons with no in vivo background signal). Kuhn et al documented the first studies using monofluorinated styrene and phenylacetylene.…”

Section: Other Phip Contrast Agents Under Developmentmentioning

confidence: 99%

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Parahydrogen‐Based Hyperpolarization for Biomedicine

et al. 2018

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Magnetic resonance (MR) is one of the most versatile and useful physical effects used for human imaging, chemical analysis, and the elucidation of molecular structures. However, its full potential is rarely used, because only a small fraction of the nuclear spin ensemble is polarized, that is, aligned with the applied static magnetic field. Hyperpolarization methods seek other means to increase the polarization and thus the MR signal. A unique source of pure spin order is the entangled singlet spin state of dihydrogen, parahydrogen (pH ), which is inherently stable and long-lived. When brought into contact with another molecule, this "spin order on demand" allows the MR signal to be enhanced by several orders of magnitude. Considerable progress has been made in the past decade in the area of pH -based hyperpolarization techniques for biomedical applications. It is the goal of this Review to provide a selective overview of these developments, covering the areas of spin physics, catalysis, instrumentation, preparation of the contrast agents, and applications.

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Section: How It Work: Principles Of Parahydrogen-based Polarizationmentioning

confidence: 99%

Section: Production Of Parahydrogenmentioning

confidence: 99%

Section: Converting the Ph 2 Spin Order Into Hyperpolarizationmentioning

confidence: 99%

Section: Homogeneous Sabre Catalysismentioning

confidence: 99%

Section: Other Phip Contrast Agents Under Developmentmentioning

confidence: 99%

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Parahydrogen‐Based Hyperpolarization for Biomedicine

et al. 2018

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Parawasserstoff‐basierte Hyperpolarisierung für die Biomedizin

et al. 2018

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Die Magnetresonanz (MR) von Kernspins ist einer der nützlichsten physikalischen Effekte für die humane Bildgebung, ebenso wie für die Aufklärung von molekularen Strukturen und die chemische Analyse. Das volle Potential der MR kann jedoch kaum genutzt werden, da nur ein geringer Bruchteil aller Kernspins polarisiert, sprich in einem äußeren magnetischen Feld ausgerichtet werden. Hyperpolarisierungsmethoden versuchen, die Polarisierung und damit das MR‐Signal auf anderem Wege zu erhöhen. Eine einzigartige Quelle reiner Spinordnung ist das langlebige, verschränkte Kernspin‐Singulett‐Isomer des Wasserstoffmoleküls, genannt Parawasserstoff (pH2). Mithilfe dieser “Spinordnung auf Abruf” kann das MR‐Signal um mehrere Größenordnungen verstärkt werden, wenn pH2 in Kontakt mit einem anderen Molekül gebracht wird. In Bezug auf eine biomedizinische Anwendung von pH2‐hyperpolarisierten Kontrastmitteln haben in den letzten zehn Jahren beeindruckende Fortschritte stattgefunden. Das Ziel dieses Aufsatzes ist es, diese Entwicklungen in den Bereichen der Spinphysik, Katalyse, Instrumentierung, Kontrastmittel und Anwendungen gebündelt und verständlich darzustellen.

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