• transfer spectroscopy
  • His recent work has focused on developing new NMR methods (such as paramagnetic relaxation enhancement, dark state exchange saturation transfer spectroscopy and lifetime line broadening) to characterize the structure and dynamics of sparsely-populated states of macromolecules, which are important in macromolecular interactions but invisible to conventional structural and biophysical techniques. (wikipedia.org)
  • atoms
  • These properties are fundamentally the same as those used in the more familiar magnetic resonance imaging (MRI), but the molecular applications use a somewhat different approach, appropriate to the change of scale from millimeters (of interest to radiologists) to nanometers (bonded atoms are typically a fraction of a nanometer apart), a factor of a million. (wikipedia.org)
  • These have heralded the advent of a number of extremely powerful procedures among which may be mentioned: (a) new pulse sequences for the unambiguous assignments of methyl, methylene, methine, and quaternary carbon atoms, side-stepping the difficulties associated with the overlapping of multiplets in the normal off-resonances measurements. (springer.com)
  • This type of spectroscopy determines the physical and chemical properties of atoms or the molecules in which they are contained. (wikipedia.org)
  • Russell H. Varian filed the "Method and means for correlating nuclear properties of atoms and magnetic fields", U.S. Patent 2,561,490 on July 24, 1951. (wikipedia.org)
  • structures
  • It is useful for molecules of up to 100 nucleotides, and as of 2003, nearly half of all known RNA structures had been determined by NMR spectroscopy. (wikipedia.org)
  • The NMR‐based determination of high‐resolution three‐dimensional (3D) structures by NMR spectroscopy in solution is especially useful for small‐to‐medium sized RNA molecules like aptamers and small ribozymes, but has also been achieved for RNAs up to about 100 nucleotides in total size. (els.net)
  • High‐resolution NMR spectroscopy in solution is a powerful method to determine the 3D structures of small and medium sized RNA molecule. (els.net)
  • coherence
  • In 1984 he published with Herbert Kogler and Richard R. Ernst a pivotal article in Journal of Magnetic Resonance where they described how to design phase cycles allowing the selection of specific coherence-transfer pathways in NMR pulse experiment. (wikipedia.org)
  • Gradient
  • Since the resolution of the imaging technique depends on the magnitude of magnetic field gradient, many efforts are made to develop increased field strength, often using superconductors. (wikipedia.org)
  • The radio signal may be made to encode position information by varying the main magnetic field using gradient coils. (wikipedia.org)
  • The major components of an MRI scanner are: the main magnet, which polarizes the sample, the shim coils for correcting shifts in the homogeneity of the main magnetic field, the gradient system which is used to localize the MR signal and the RF system, which excites the sample and detects the resulting NMR signal. (wikipedia.org)
  • spectrum
  • Accuracy of integration can be improved by inserting a chiral derivatizing agent with a nucleus other than hydrogen or carbon, then reading the heteronuclear NMR spectrum: for example fluorine-19 NMR or phosphorus-31 NMR. (wikipedia.org)
  • utilizes
  • A new strategy recently developed in our group utilizes heteronuclear 3D NMR 2,3 and isotope enrichment to a large extent to solve the problem. (springer.com)
  • peaks
  • The use of higher strength magnetic fields result in clear resolution of the peaks and is the standard in industry. (wikipedia.org)
  • As with NMR spectroscopy in general, good resolution requires a high signal-to-noise ratio, clear separation between peaks for each stereoisomer, and narrow line width for each peak. (wikipedia.org)
  • elucidation
  • He conducted preliminary investigations into the utilization of indirect covariance NMR spectroscopy as an alternative means of evaluating NMR data for structure characterization and Computer-Assisted Structure Elucidation. (wikipedia.org)
  • Historically, Wilkinson's catalyst has been a paradigm in catalytic studies leading to several advances in the field such as the implementation of some of the first heteronuclear magnetic resonance studies for its structural elucidation in solution (31P), parahydrogen-induced polarization spectroscopy to determine the nature of transient reactive species, or one of the first detailed kinetic investigation by Halpern to elucidate the mechanism. (wikipedia.org)
  • chemical shifts
  • Both use intense applied magnetic fields (H0) in order to achieve dispersion and very high stability to deliver spectral resolution, the details of which are described by chemical shifts, the Zeeman effect, and Knight shifts (in metals). (wikipedia.org)
  • constants
  • Vicinal heteronuclear H-C-O-C coupling constants are used to study torsional angles along glycosidic bond between sugars or along exocyclic fragments, thus revealing a molecular conformation. (wikipedia.org)
  • Whereas, measurements of diffusion constants (diffusion ordered spectroscopy or DOSY) are done the sample stationary and spinning off, and flow cells can be used for online analysis of process flows. (wikipedia.org)
  • 1990
  • He also worked with Christophe Copéret on hybrid polarizing solids (HYPSOs) for Magnetic resonance imaging with 1990: National Latsis Prize awarded by the Latsis Foundation. (wikipedia.org)
  • detection
  • During his time at Merck he has continued to explore the limits of detection for low level samples by heteronuclear 2D NMR using newly developed 1.7 mm Micro CryoProbe™ technology. (wikipedia.org)
  • placed in a magnetic field
  • When placed in a magnetic field, NMR active nuclei (such as 1H or 13C) absorb electromagnetic radiation at a frequency characteristic of the isotope. (wikipedia.org)
  • Rabi, Bloch, and Purcell observed that magnetic nuclei, like 1 H and 31 P , could absorb RF energy when placed in a magnetic field and when the RF was of a frequency specific to the identity of the nuclei. (wikipedia.org)
  • organic
  • Most frequently, NMR spectroscopy is used by chemists and biochemists to investigate the properties of organic molecules, although it is applicable to any kind of sample that contains nuclei possessing spin. (wikipedia.org)
  • indirect
  • He has also explored the use of unsymmetrical indirect covariance NMR processing methods to define 13C-15N and 13C-13C heteronuclear connectivity networks. (wikipedia.org)
  • resonate
  • It is common to refer to a 21 T magnet as a 900 MHz magnet, although different nuclei resonate at a different frequency at this field strength in proportion to their nuclear magnetic moments. (wikipedia.org)
  • Bloch
  • The Purcell group at Harvard University and the Bloch group at Stanford University independently developed NMR spectroscopy in the late 1940s and early 1950s. (wikipedia.org)
  • methods
  • His ongoing research interests have centered on the development of new NMR methods for the characterization of impurities and degradants of pharmaceuticals focusing on the exploration of new NMR probe technologies for the characterization of extremely small samples using heteronuclear 2D-NMR methods. (wikipedia.org)
  • molecule
  • The intramolecular magnetic field around an atom in a molecule changes the resonance frequency, thus giving access to details of the electronic structure of a molecule and its individual functional groups. (wikipedia.org)
  • Laboratory
  • He is professor of chemistry at the Department of Chemistry at the École Normale Supérieure (ENS) in Paris and professeur honoraire at the Laboratory of Biomolecular Magnetic Resonance of the École Polytechnique Fédérale de Lausanne (EPFL). (wikipedia.org)