Geoffrey Bodenhausen

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To excite and refocus single quantum coherences in a three-level system with a quadrupolar interaction, it is possible to use frequency-modulated pulses with two diverging frequency components that are swept simultaneously through the two single-quantum transitions. This is achieved by time-dependent amplitude-modulation of the carrier frequency, so as to generate two sidebands with frequencies that are diverging (or converging) sym. with respect to the carrier frequency. Simulations and expts. show that su

It is shown by simulation and expt. that frequency-modulated "chirp" pulses are very effective for exciting multiple-quantum coherences over large bandwidths. Chirp pulses can be considered as an alternative to composite pulses to combat the effects of large offsets and tilted effective fields. By way of example, the excitation is discussed of double-quantum coherences for pairs of scalar-coupled spin I = 1/2 nuclei over large ranges of chem. shifts. Refocusing of the phase dispersion of double-quantum co

Techniques are described for displaying NMR responses as a function of 2 independent frequency parameters, with particular emphasis on the presentation of 13C spectra with the chem. shift information in 1-dimension and the H-13C splittings in the 2nd dimension. The resolving power for these spin multiplets can be significantly better than in conventional NMR, since the linewidths are detd. principally by spin-spin relaxation effects rather than by field inhomogeneity. Modulation is imposed on 13C spin echoe

In the present study the authors examine the thermodn. of binding of two related pyrazine-derived ligands to the major urinary protein, MUP-I, using a combination of isothermal titrn. calorimetry (ITC), x-ray crystallog., and NMR backbone 15N and Me side-chain 2H relaxation measurements. Global thermodn. data derived from ITC indicate that binding is driven by favorable enthalpic contributions, rather than the classical entropy-driven hydrophobic effect. Unfavorable entropic contributions from the protein b

A new technique is presented for studying chem. exchange in solids under conditions of magic angle spinning (MAS); it is based on the original 2-dimensional exchange expt. but uses the combination of a TOSS (total suppression of sidebands) sequence with its time-reversed counterpart in the 1st dimension to effect evolution under the isotropic chem. shift alone. Pure absorption-mode spectra can then be obtained in the usual way. One version of the expt. also uses TOSS at the start of acquisition, producing a

The document relates to a method for the determination of the binding properties of at least one first chemical compound to at least one second chemical compound between a free essentially dissociated state and a bound essentially associated state by using ...

A method for nuclear magnetic resonance (NMR) spectroscopy of a sample comprises preparation of the sample and carrying out an NMR spectroscopy measurement. Preparation includes excitation of long lived coherences (LLC) between the singlet state S0 and the ...

In solids that are spinning about the magic angle, trains of short pulses in the manner of Delays Alternating with Nutations for Tailored Excitation (DANTE) allow one to improve the efficiency of the excitation of magnetization compared to rectangular puls ...

In a bilingual paper entitled 'Bibliometrics as weapons of mass citation - La bibliometrie comme arme de citation massive',([1]) recently translated into English,([2]) we have argued that the current fashion of ranking people, papers and journals is anything but harmless. The point was forcefully supported by Richard Ernst in a post-face entitled 'The Follies of Citation Indices and Academic Ranking Lists.([3,4]) We received a surprising number of passionate responses, such as 'It's written out of my heart'

The angle Theta(C(alpha)H(alpha)),NH(N) subtended by the internuclear vectors 13C(alpha)-H(alpha) and 15N-H(N) in doubly-labeled proteins can be determined by observing the effect of cross-correlation between the dipolar interactions on zero- and double-quantum coherences involving 13C(alpha) and 15N. Two complementary 2D experiments with the appearance of 15N-HN correlation spectra yield signal intensities that depend on the rate of interconversion through cross-correlated relaxation of in-phase and doubly

Cross-correlation between the fluctuations of 13Ca-Ha interactions affects the relaxation behavior of two-spin coherences (zero- and double-quantum coherences) involving the 13Ca nuclei of two successive amino acid residues. The cross-correlation rates are shown to depend on a dihedral angle S defined by two planes subtended by the atoms {Ha(i-1),13Ca(i-1),13Ca(i)} and {13Ca(i-1),13Ca(i),Ha(i)}. This dihedral angle is related to the secondary structure of a protein, and can be used as a constraint in variou

This method measures cross relaxation rates in highly resolving NMR spectroscopy, where the sample substance is dissolved in a liq. and has nuclei A and X which have different chem. shifts WA and WX in a homogeneous static magnetic field Bo in the direction of the z-axis. The orientation of the longitudinal components I2A and I2X bring about the magnetization vectors IA and IX of the nuclei A and X during a time interval tan and irradn. with a constructed high-frequency field. Subsequently a longitudinal ma

Exchange transferred effects in soln.-state NMR expts. allow one to det. the conformation of ligands that are weakly bound to macromols. Exchange-transferred nuclear Overhauser effect spectroscopy (TR-NOESY) provides information about internuclear distances in a ligand in the bound state. Recently the possibility of obtaining dihedral angle information from a ligand in the bound state by exchange-transferred cross-correlation spectroscopy (TR-CCSY) was reported. In both cases the anal. of the signal amplitu

The measurement of the migration of longitudinal 2-spin order by 2-dimensional (2D) exchange spectroscopy or by selective 1-dimensional (1D) methods (2D or 1D zz-exchange spectroscopy) allows unambiguous differentiation between chem. exchange and cross-relaxation processes in complex nuclear spin systems, provided a fragment with at least 2 coupled spins is transferred from 1 site to another in the exchange process. Compared to conventional 2D exchange spectroscopy, zz-exchange studies have the advantage th

In a study of heteronuclear J NMR spectroscopy, the radio frequency phase of the initial 90 Deg pulse was shifted together with the phase of the refocusing pulse. In heteronuclear spectra, the phase cycling method shifts all resonances by DF1 = (4Dt-1)-1 corresponding to 1/2 of the spectral width in the F1 frequency domain. Thus the proton transmitter can be set in the middle of the proton spectrum without introducing aliasing problems, and the technique does not interfere with ordinary quadrature detection

New NMR (NMR) methods are described for the measurement of cross-correlation rates of zero- and double-quantum coherences involving two nitrogen nuclei belonging to successive amino acids in proteins and peptides. Rates due to the concerted fluctuations of two NHN dipole-dipole interactions and to the correlated modulations of two nitrogen chem. shift anisotropies have been obtained in a sample of doubly labeled Ubiquitin. Ambiguities in the detn. of dihedral angles can be lifted by comparison of different

Two sets of cross-correlated relaxation rates involving chem. shift anisotropy and dipolar interactions have been measured in an RNA kissing complex. In one case, both the CSA and dipolar interaction tensors are located on the same nucleotide base and are rigidly fixed with respect to each other. In the other case, the CSA tensor is located on the nucleotide base whereas the dipolar interaction is located on the adjoining ribose unit. Anal. of the measured rates in terms of isotropic or anisotropic rotation

Chirp pulses were used to excite transverse magnetization over bandwidths that are .apprx.50 times wider than the amplitude of the RF field. Exptl. profiles are shown of the amplitudes and phases as a function of offset. The efficiency of refocusing by chirp pulses over large bandwidths is proven by expt. RF inhomogeneity leads to an attenuation of the echo intensity but does not perturb its phase. The excitation of multiple-quantum coherences and their reconversion into single-quantum magnetization by chir

Dynamic nuclear polarization at 1.2 K and 6.7 T allows one to achieve spin temperatures on the order of a few millikelvin, so that the high-temperature approximation (Delta E < kT) is violated for the nuclear Zeeman interaction Delta E = gamma B(0)h/(2 pi) ...

In magnetic resonance imaging (MRI), it is possible to cancel the effects of severe inhomogeneities of the magnetic field even if the field profile is unknown. The new ‘cross-encoded’ method is based on adiabatic frequency-modulated pulses combined with tw ...

Geoffrey Bodenhausen

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Divergent double chirp pulses for refocusing quadrupolar interactions

Broadband multiple-quantum nuclear magnetic resonance with frequency-modulated \"chirp\" pulses: applications to pairs of scalar-coupled spin I=1/2 nuclei

Double Fourier transformation in high-resolution NMR

Thermodynamics of Binding of 2-Methoxy-3-isopropylpyrazine and 2-Methoxy-3-isobutylpyrazine to the Major Urinary Protein

Pure absorption-mode, chemical-exchange, nuclear magnetic resonance spectroscopy with suppression of spinning sidebands in a slowly rotating solid

Method for the nmr based determination of the affinity of drugs for a target protein

Method for nuclear magnetic resonance (NMR) spectroscopy measurements using long-lived coherences (LLC)

Uniform broadband excitation of crystallites in rotating solids using interleaved sequences of delays alternating with nutation

The Kinship or k-Index as an Antidote Against the Toxic Effects of h-Indices

Efficient determination of angles subtended by C(alpha)-H(alpha) and N-H(N) vectors in proteins via dipole-dipole cross-correlation

Relative Orientation of CaHa-Bond Vectors of Successive Residues in Proteins through Cross-Correlated Relaxation in NMR

Measurement of cross relaxation rates between selected nucleus pairs in NMR spectroscopy

Transferred cross-relaxation and cross-correlation in NMR. Effects of intermediate exchange on the determination of the conformation of bound ligands

Exchange of two-spin order in nuclear magnetic resonance: separation of exchange and cross-relaxation processes

Heteronuclear J spectroscopy

Correlated motions of successive amide N-H bonds in proteins

Cross correlations between 13C-1H dipolar interactions and 15N chemical shift anisotropy in nucleic acids

Experimental aspects of chirp NMR spectroscopy

Measuring absolute spin polarization in dissolution-DNP by Spin PolarimetrY Magnetic Resonance (SPY-MR)

Cross-encoded magnetic resonance imaging in inhomogeneous fields