What the experts say

Expert opinions on FFC NMR relaxometry and Stelar relaxometers:

Prof. Rainer Kimmich

University of Ulm, Germany

“In our research group at the University of Ulm, we have been using homebuilt field-cycling NMR relaxometers over decades. Several generations of gradually improved versions have been designed and employed in the course of the years. However, only after we had purchased a STELAR Spinmaster more than ten years ago as our first commercial instrument of this sort, we reached the performance and the ease of use our students needed for a number of quite demanding applications. The examined systems include polymers, porous media, and liquid crystals. The objectives of our experiments partially referred to issues of molecular dynamics the exploration of which requires peculiar experimental set-ups. Examples of such unconventional studies have been spin-lattice relaxation dispersion in partially deuterated or fluorine-containing samples, molecular reorientations modified by superimposed hydrodynamic flow, and the effect of ultrasound on liquid-crystalline order fluctuations. The Spinmaster relaxometer is a mature tool leaving ample space for the researcher’s imaginations and inspirations.”

Prof. Kimmich has around 180 publications, including:

Field-cycling NMR relaxometry

R. Kimmich and E. Anoardo

Progress in Nuclear Magnetic Resonance Spectroscopy e 44 (2004) 257-320.

Prof. Bertil Halle

University of Lund, Sweden

“Stelar has served us well over the past 15 years by providing reliable field-cycling instruments that have opened up a wide range of new research possibilities. In particular, our current Stelar 1T Spinmaster Fast Field-Cycling instrument has been indispensable in providing accurate deuteron relaxation dispersion data down to 1.5 kHz in our studies of internal water molecules in proteins, polymer gels, bacteria and endospores.”

Prof. Halle’s publications include:

Mechanism of 1H-14N cross-relaxation in immobilized proteins.
E P Sunde & B Halle, J Magn Reson 203, 257-273 (2010).

The physical state of water in bacterial spores.
E P Sunde, P Setlow, L Hederstedt & B Halle, Proc Natl Acad Sci USA 106, 19334-19339 (2009).

Nanosecond to microsecond protein dynamics probed by magnetic relaxation dispersion of buried water molecules.
E Persson & B Halle, J Am Chem Soc 130, 1774-1787 (2008).

Cell water dynamics on multiple time scales.
E Persson & B Halle, Proc Natl Acad Sci USA 105, 6266-6271 (2008).

Molecular basis of water proton relaxation in gels and tissue.
F Vaca Chávez & B Halle, Magn Reson Med 56, 73–81 (2006).

Prof. Robert G. Bryant

University of Virginia, Charlottesville (VA), USA

“Magnetic Relaxation Dispersion (MRD) provides a powerful means to explore molecular dynamics directly from the time range from picoseconds to milliseconds. In liquids, spectral selection gives molecule specific information including intramolecular dynamics, and translational or rotational correlation times. A virtue of the field or Larmor frequency dependence measurement is that it is unnecessary to know the strength of the interactions involved in order to extract the dynamics because the time constants are provided by the transition frequencies seen in the MRD profiles. Because the radio frequency fields easily penetrate most materials, MRD opens the window to slow dynamics often difficult to study by other spectroscopic methods in heterogeneous materials that may include both liquids and solids.”

Prof. Bryant’s publications include:

Dimensionality of Diffusive Exploration at the Protein Interface in Solution
D. S. Grebenkov, Y. A. Goddard, G. Diakova, J.-P. Korb, R. G. Bryant, J. Phys. Chem. B, 113,13347-13356(2009)

Water and Backbone Dynamics in a Hydrated Protein
G. Diakova, Y. Goddard, J.-P. Korb, R. G. Bryant. Biophys. J. 98, 138-146(2010).

Dynamics of Water in and Around Proteins Characterized by 1H Spin-Lattice Relaxometry
R. G. Bryant. Comptes Rendus Physique 11(2) 128-135(2010).

Water-Proton-Spin–Lattice-Relaxation Dispersion of Paramagnetic Protein Solutions
G. Diakova, Y. Goddard, J.-P. Korb, R. G. Bryant, J. Magn. Reson. 208, 195-203(2011).

The Magnetic Field Dependence of Water T1 in tissues
G. Diakova, J.-P. Korb, R. G. Bryant, Magn. Reson. Med. (published electronically Dec. 5, 2011, DOI.10.1002/mrm.23234, to be printed in July 2012

Prof. Pellegrino Conte

University of Palermo, Italy

“Fast field cycling NMR relaxometry performed either by Spinmaster or Smartracer revealed its powerfulness in agro-food and environmental chemistry. We were able to monitor differences in pistachio oils obtained from different cultivars which were harvested in different locations. In addition, the nature of surface interactions between water and biochar (nowadays applied as a soil amendment) have been investigated and understood.”

Prof. Conte’s publications include:

Dynamics of hyaluronan aqueous solutions as assessed by fast field cycling NMR relaxometry
A. Prusova, P. Conte, J. Kucerik, G. Alonzo, Analytical and Bioanalytical Chemistry 397: 7, 3023-28 (2010).

Applicability of solid state fast field cycling NMR relaxometry in understanding relaxation properties of leaves and leaf-litters
A. E. Berns, S. Bubici, C. De Pasquale, G. Alonzo, P. Conte, Organic Geochemistry 42: 8, 978-984 (2011).

Fast field cycling NMR relaxometry characterization of biochars obtained from an industrial thermochemical process
C. De Pasquale, V. Marsala, A. E. Berns, M. Valagussa, A. Pozzi, G. Alonzo, P. Conte, Journal of Soils and Sediments (2012) doi: 10.1007/s11368-012-0489-x.

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