Reynolds, S., et al., A system for accurate and automated injection of hyperpolarized substrate with minimal dead time and scalable volumes over a large range. J Magn Reson, 2013. 239C(0): p. 1-8.
Over recent years hyperpolarization by dissolution dynamic nuclear polarization has become an established technique for studying metabolism in vivo in animal models. Temporal signal plots obtained from the injected metabolite and daughter products, e.g. pyruvate and lactate, can be fitted to compartmental models to estimate kinetic rate constants. Modeling and physiological parameter estimation can be made more robust by consistent and reproducible injections through automation. An injection system previously developed by us was limited in the injectable volume to between 0.6 and 2.4ml and injection was delayed due to a required syringe filling step. An improved MR-compatible injector system has been developed that measures the pH of injected substrate, uses flow control to reduce dead volume within the injection cannula and can be operated over a larger volume range. The delay time to injection has been minimized by removing the syringe filling step by use of a peristaltic pump. For 100mul to 10.000ml, the volume range typically used for mice to rabbits, the average delivered volume was 97.8% of the demand volume. The standard deviation of delivered volumes was 7mul for 100mul and 20mul for 10.000ml demand volumes (mean S.D. was 9 ul in this range). In three repeat injections through a fixed 0.96mm O.D. tube the coefficient of variation for the area under the curve was 2%. For in vivo injections of hyperpolarized pyruvate in tumor-bearing rats, signal was first detected in the input femoral vein cannula at 3-4s post-injection trigger signal and at 9-12s in tumor tissue. The pH of the injected pyruvate was 7.1+/-0.3 (mean+/-S.D., n=10). For small injection volumes, e.g. less than 100mul, the internal diameter of the tubing contained within the peristaltic pump could be reduced to improve accuracy. Larger injection volumes are limited only by the size of the receiving vessel connected to the pump.
Transmit-Only/Receive-Only Radiofrequency System for Hyperpolarized 13C MRS Cardiac Metabolism Studies in Pigs
From The DNP-NMR Blog:
Transmit-Only/Receive-Only Radiofrequency System for Hyperpolarized 13C MRS Cardiac Metabolism Studies in Pigs
Giovannetti, G., et al., Transmit-Only/Receive-Only Radiofrequency System for Hyperpolarized 13C MRS Cardiac Metabolism Studies in Pigs. Appl. Magn. Reson., 2013. 44(10): p. 1125-1138.
http://dx.doi.org/10.1007/s00723-013-0477-3
Fast and accurate algorithm for the simulation of NMR spectra of large spin systems.
Fast and accurate algorithm for the simulation of NMR spectra of large spin systems.
Fast and accurate algorithm for the simulation of NMR spectra of large spin systems.
J Magn Reson. 2011 Apr;209(2):123-30
Authors: Castillo AM, Patiny L, Wist J
The computational cost for the simulation of NMR spectra grows exponentially with the number of nuclei. Today, the memory available to store the Hamiltonian limits the size of the system that can be studied. Modern computers enable to tackle systems containing up to 13 spins , which obviously does not...
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07-23-2011 08:54 AM
[NMR paper] Automated protein fold determination using a minimal NMR constraint strategy.
Automated protein fold determination using a minimal NMR constraint strategy.
Related Articles Automated protein fold determination using a minimal NMR constraint strategy.
Protein Sci. 2003 Jun;12(6):1232-46
Authors: Zheng D, Huang YJ, Moseley HN, Xiao R, Aramini J, Swapna GV, Montelione GT
Determination of precise and accurate protein structures by NMR generally requires weeks or even months to acquire and interpret all the necessary NMR data. However, even medium-accuracy fold information can often provide key clues about protein evolution...
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11-24-2010 09:01 PM
[NMR paper] Small volume flow probe for automated direct-injection NMR analysis: design and perfo
Small volume flow probe for automated direct-injection NMR analysis: design and performance.
Related Articles Small volume flow probe for automated direct-injection NMR analysis: design and performance.
J Magn Reson. 2000 Mar;143(1):69-78
Authors: Haner RL, Llanos W, Mueller L
A detailed characterization of an NMR flow probe for use in direct-injection sample analysis is presented. A 600-MHz, indirect detection NMR flow probe with a 120-microl active volume is evaluated in two configurations: first as a stand-alone small volume probe for the...
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11-18-2010 09:15 PM
[NMR paper] Proton NMR studies of a large protein. pH, substrate titrations, and NOESY experiment
Proton NMR studies of a large protein. pH, substrate titrations, and NOESY experiments with perdeuterated yeast phosphoglycerate kinase containing histidine residues.
Related Articles Proton NMR studies of a large protein. pH, substrate titrations, and NOESY experiments with perdeuterated yeast phosphoglycerate kinase containing histidine residues.
J Magn Reson B. 1994 Oct;105(2):157-66
Authors: Pappu KM, Serpersu EH
Fully deuterated yeast phosphoglycerate kinase (PGK) was prepared biosynthetically with only histidine side chains of normal...
A system for accurate and automated injection of hyperpolarized substrate with minimal dead time and scalable volumes over a large range
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