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  • 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)
  • protons
  • In addition to the backbone amide resonances, sidechains with nitrogen-bound protons will also produce peaks. (wikipedia.org)
  • All isotopes that contain an odd number of protons and/or neutrons (see Isotope) have an intrinsic magnetic moment and angular momentum, in other words a nonzero spin, while all nuclides with even numbers of both have a total spin of zero. (wikipedia.org)
  • For example, in a 21 Tesla magnetic field, protons resonate at 900 MHz. (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)
  • 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)
  • This type of spectroscopy determines the physical and chemical properties of atoms or the molecules in which they are contained. (wikipedia.org)
  • 1996
  • In 1996 he was elected fellow of the American Physical Society "for his numerous contributions toward making magnetic resonance one of the most sophisticated and versatile methods available for gaining insight into structure and dynamics of molecules in condensed and gas phase. (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)
  • 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)
  • organic
  • As the fields are unique or highly characteristic to individual compounds, in modern organic chemistry practice, NMR spectroscopy is the definitive method to identify monomolecular organic compounds . (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)
  • 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)
  • 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)
  • protein
  • Protein nuclear magnetic resonance is performed on aqueous samples of highly purified protein. (wikipedia.org)
  • Protein NMR Spectroscopy. (wikipedia.org)
  • He is a member of the United States National Academy of Sciences, a NIH Distinguished Investigator, and the Chief of the Protein NMR Spectroscopy Section in the Laboratory of Chemical Physics of the National Institute of Diabetes and Digestive and Kidney Diseases at the National Institutes of Health. (wikipedia.org)
  • He is known for his foundational work in three-dimensional protein and nucleic acid structure determination by biomolecular NMR spectroscopy, for advancing experimental approaches to the study of large macromolecules and their complexes by NMR, and for developing NMR-based methods to study rare conformational states in protein-nucleic acid and protein-protein recognition. (wikipedia.org)
  • He has remained at the NIH ever since and is currently an NIH Distinguished Investigator and Chief of the Section on Protein NMR Spectroscopy at the NIH. (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)
  • experiment
  • Nuclear magnetic resonance was first described and measured in molecular beams by Isidor Rabi in 1938, by extending the Stern-Gerlach experiment, and in 1944, Rabi was awarded the Nobel Prize in Physics for this work. (wikipedia.org)
  • 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)
  • excitation
  • or exciting only resonances of interest ("selective excitation"), which has the additional, potentially undesired effect of distorting the peak amplitudes. (wikipedia.org)
  • 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)
  • 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)
  • 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)
  • 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)
  • 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)
  • 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)