• 제목/요약/키워드: Parahydrogen

검색결과 4건 처리시간 0.016초

Low Cost and Portable Parahydrogen Generator for the PHIP

  • Kwon, Soonmo;Min, Sein;Chae, Heelim;Namgoong, Sung Keon;Jeong, Keunhong
    • 한국자기공명학회논문지
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    • 제21권4호
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    • pp.126-130
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    • 2017
  • In the developed NMR hyperpolarization techniques, Parahydrogen-Induced Polarization (PHIP) technique is widely utilized to overcome the low sensitivity of the NMR/MRI. Parahydrogen generator is essential to produce high spin order of parahydrogen molecule. Commercial parahydrogen generator is well developed with user-friendly systems. However, it has drawbacks of long preparation time (~ 2h including cooling down time of 1h) and high cost (~ 200 million won) for the commercial setup. We designed a simple and portable parahydrogen generating system with low cost (~ 2 million won), which produce polarization in less than 1 min. With the designed parahydrogen generator, we successfully performed the PHIP with Wilkinson's catalyst on styrene. This study will broaden the parahydrogen based polarization transfer study on many researchers by providing the simple portable and low cost parahydrogen generator.

Hyperpolarization Researches with Parahydrogen

  • Shim, Joongmoo;Jeong, Keunhong
    • 한국자기공명학회논문지
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    • 제22권1호
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    • pp.1-9
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    • 2018
  • Among several NMR hyperpolarization techniques, parahydrogen-based hyperpolarization technique is recently extensively utilized to enhance the sensitivity of the conventional NMR/MRI spectroscopy. Two mostly investigated research topics are PHIP (Parahydrogen Induced Polarization) and SABRE (Signal Amplification By Reversible Exchange), which are commonly using the parahydrogen as the source of hyperpolarization. Those researches have been considered as the promising techniques that could provide hyperpolarized states on the ambient substrates including biologically important materials. Therefore, based on their potentials, we briefly reviewed several important experimental results on those topics after introducing the basic principle of parahydrogen and its generation with conceptual explanations. We hope this review will broaden the parahydrogen-based hyperpolarization transfer study on many researches in Korea.

The ALTADENA and PASADENA studies in benchtop NMR spectrometer

  • So, Howon;Jeong, Keunhong
    • 한국자기공명학회논문지
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    • 제23권1호
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    • pp.6-11
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    • 2019
  • Parahydrogen induced hyperpolarization (PHIP) technique is extensively studied to increase the sensitivity of the conventional NMR spectroscopy and recently try to apply this advanced technique into the revolutionary future of the MRI. The other hyperpolarization technique, which is widely utilized, is DNP (Dynamic Nuclear Polarization)-based hyperpolarization one. Despite its great advances in these fields, it contains several drawbacks to overcome: fast relaxation time, expensive equipment is needed, long build-up time is required (several hours), and batch scale material is hyperpolarized. To overcome all those limitations, one can effectively harness the hyperpolarized spin state of parahydrogen. One important step for utilizing the spin state of parahydrogen is doing well-developed experiments of ALTADENA and PASADENA. Based on those concepts, we successfully obtain the hydrogenation signals of ALTADENA and PASADENA from styrene by using benchtop NMR spectrometer. Also those signals were conceptually analyzed and confirmed with different mechanisms. To our best knowledge, those experiments using 1.4T (benchtop NMR) is the first reported one. Considering these experiments, we hope that parahydrogen-based hyperpolarization transfer studies in NMR/MRI will be broadened in Korea in the future.

삼중점과 임계점간 파라수소의 증기압 예측 (Prediction of Vapor Pressure of Parahydrogen from the Triple to the Critical Point)

  • 정재관
    • 대한화학회지
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    • 제45권4호
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    • pp.293-297
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    • 2001
  • 문헌에 보고된 삼중점과 임계점간 기존의 파라수소 증기압 측정값을 이용하여 환원증기압과 환원온도 형태의 아래와 같은 식의 지수와 상수를 구하는데 사용하였다. $lnP_r=2.64-{\frac{2.75}{T_r}}+1.48129lnT_r+0.11T^5_r$ 증기압을 계산하기 위해서 필요한 것은 정상 끓는점($T_b$= 20.268K), 임계압력($P_c$= 1292.81 kPa) 및 임계온도($T_c$= 32.976K)뿐이며 153개 파라수소의 증기압 실험자료에 적용하여 본 결과 전체 평균편차가 0.21% 였다.

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