The spin-lattice relaxation time T1 of hyperpolarized (HP)-(129)Xe was improved at typical storage conditions (i.e. low and homogeneous magnetic fields). Very long wall relaxation times T1(wall) of about 18h were observed in uncoated, spherical GE180 glass cells of slashed circle=10cm which were free of rubidium and not permanently sealed but attached to a standard glass stopcock. An "aging" process of the wall relaxation was identified by repeating measurements on the same cell. This effect could be easily removed by repeating the initial cleaning procedure. In this way, a constant wall relaxation was ensured. The Xe nuclear spin-relaxation rate 1/T1(Xe-Xe) due to van der Waals molecules was investigated too, by admixing three different buffer gases (N2, SF6 and CO2). Especially CO2 exhibited an unexpected high efficiency (r) in shortening the lifetime of the Xe-Xe dimers and hence prolonging the total T1 relaxation even further. These measurements also yielded an improved accuracy for the van der Waals relaxation for pure Xe (with 85% (129)Xe) of T1(Xe-Xe)=(4.6+/-0.1)h. Repeating the measurements with HP (129)Xe in natural abundance in mixtures with SF6, a strong dependence of T1(Xe-Xe) and r on the isotopic enrichment was observed, uncovering a shorter T1(Xe-Xe) relaxation for the (129)Xe in natural composition as compared to the 85% isotopically enriched gas.
Xenon boost: Medical microfluidics
Xenon boost: Medical microfluidics
http://www.spectroscopynow.com/common/images/thumbnails/14641bbcd0c.jpgA microfluidic device that can generate polarised xenon-129 gas and detect it by nuclear magnetic resonance, NMR, spectroscopy at tiny concentrations has been developed by an international team. The device could give a noble boost to biomedical analysis and medical imaging.
Read the rest at Spectroscopynow.com
Hyperpolarized Xenon-Based Molecular Sensors for Label-Free Detection of analytes
From The DNP-NMR Blog:
Hyperpolarized Xenon-Based Molecular Sensors for Label-Free Detection of analytes
Garimella, P.D., et al., Hyperpolarized Xenon-Based Molecular Sensors for Label-Free Detection of analytes. J. Am. Chem. Soc., 2013. 136(1): p. 164-168.
http://pubs.acs.org/doi/abs/10.1021/ja406760r
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02-28-2014 07:08 PM
Nanoemulsion Contrast Agents with Sub-picomolar Sensitivity for Xenon NMR
From The DNP-NMR Blog:
Nanoemulsion Contrast Agents with Sub-picomolar Sensitivity for Xenon NMR
Stevens, T.K., R.M. Ramirez, and A. Pines, Nanoemulsion Contrast Agents with Sub-picomolar Sensitivity for Xenon NMR. J. Am. Chem. Soc., 2013. 135(26): p. 9576-9579.
http://dx.doi.org/10.1021/ja402885q
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11-21-2013 01:14 AM
Nanoemulsion Contrast Agents with Sub-picomolar Sensitivityfor Xenon NMR
Nanoemulsion Contrast Agents with Sub-picomolar Sensitivityfor Xenon NMR
Todd K. Stevens, R. Matthew Ramirez and Alexander Pines
http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jacsat/0/jacsat.ahead-of-print/ja402885q/aop/images/medium/ja-2013-02885q_0003.gif
Journal of the American Chemical Society
DOI: 10.1021/ja402885q
http://feeds.feedburner.com/~ff/acs/jacsat?d=yIl2AUoC8zA
http://feeds.feedburner.com/~r/acs/jacsat/~4/tOmAQoYFsGk
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06-19-2013 08:08 AM
[NMR paper] Dynamics of xenon binding inside the hydrophobic cavity of pseudo-wild-type bacteriophage T4 lysozyme explored through xenon-based NMR spectroscopy.
Dynamics of xenon binding inside the hydrophobic cavity of pseudo-wild-type bacteriophage T4 lysozyme explored through xenon-based NMR spectroscopy.
Related Articles Dynamics of xenon binding inside the hydrophobic cavity of pseudo-wild-type bacteriophage T4 lysozyme explored through xenon-based NMR spectroscopy.
J Am Chem Soc. 2005 Aug 24;127(33):11676-83
Authors: Desvaux H, Dubois L, Huber G, Quillin ML, Berthault P, Matthews BW
Wild-type bacteriophage T4 lysozyme contains a hydrophobic cavity with binding properties that have been...
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12-01-2010 06:56 PM
[NMR paper] Improvement of hydrogen bond geometry in protein NMR structures by residual dipolar c
Improvement of hydrogen bond geometry in protein NMR structures by residual dipolar couplings--an assessment of the interrelation of NMR restraints.
Related Articles Improvement of hydrogen bond geometry in protein NMR structures by residual dipolar couplings--an assessment of the interrelation of NMR restraints.
J Biomol NMR. 2004 Jan;28(1):31-41
Authors: Jensen PR, Axelsen JB, Lerche MH, Poulsen FM
We have examined how the hydrogen bond geometry in three different proteins is affected when structural restraints based on measurements of...
Systematic T1 improvement for hyperpolarized (129)xenon
Linear Mode
