Warren Warren

Overview:

Our work focuses on the design and application of what might best be called novel pulsed techniques, using controlled radiation fields to alter dynamics. The heart of the work is chemical physics, and most of what we do is ultrafast laser spectroscopy or nuclear magnetic resonance. It generally involves an intimate mixture of theory and experiment: recent publications are roughly an equal mix of pencil- and-paper theory, computer calculations with our workstations, and experiments. Collaborations also play an important role, particularly for medical applications.

Positions:

James B. Duke Distinguished Professor of Chemistry

Chemistry
Trinity College of Arts & Sciences

Professor of Chemistry

Chemistry
Trinity College of Arts & Sciences

Professor of Biomedical Engineering

Biomedical Engineering
Pratt School of Engineering

Professor of Radiology

Radiology
School of Medicine

Professor of Physics

Physics
Trinity College of Arts & Sciences

Member of the Duke Cancer Institute

Duke Cancer Institute
School of Medicine

Education:

M.S. 1979

University of California - Berkeley

Ph.D. 1980

University of California - Berkeley

Grants:

GAANN - Department of Chemistry

Administered By
Chemistry
Awarded By
Department of Education
Role
Mentor
Start Date
End Date

Probing Hyperpolarized 15N2-diazirine as A Universal Molecular Tag in MRI

Administered By
Chemistry
Awarded By
National Institutes of Health
Role
Collaborator
Start Date
End Date

Improving Understanding, Utility and Generality of Hyperpolarized, Long-lived Spin States in Magnetic Resonance

Administered By
Chemistry
Awarded By
National Science Foundation
Role
Principal Investigator
Start Date
End Date

Making Clinical Scale Hyperpolarization Simple, Fast, and Cheap

Administered By
Chemistry
Awarded By
National Institutes of Health
Role
Principal Investigator
Start Date
End Date

Molecular imaging of in vivo metabolism with a hyperpolarized vitamin shot

Administered By
Chemistry
Awarded By
National Institutes of Health
Role
Co Investigator
Start Date
End Date

Publications:

Femtosecond polarization detection using high-speed pulse shaping

We demonstrate a method for femtosecond, phase sensitive detection of optical polarization, using an acousto-optic pulse shaper to create a sequence of up to several hundred phase coherent pulses. Essential to this method is the ability of the acousto-optic pulse shaper to update the phase relation of the pulses in the sequence on a nanosecond timescale. The method is demonstrated by measuring the optical free induction decay of rubidium vapor, and can be particularly useful for experiments involving very low or very high optical densities. It can easily be extended to multidimensional spectroscopy.
Authors
Keusters, D; Tian, P; Warren, WS
MLA Citation
Keusters, D., et al. “Femtosecond polarization detection using high-speed pulse shaping.” Optics Infobase Conference Papers, 2000, pp. 679–81.
URI
https://scholars.duke.edu/individual/pub1529993
Source
scopus
Published In
Optics Infobase Conference Papers
Published Date
Start Page
679
End Page
681

The generation, amplification and characterisation of shaped ultrafast laser pulses, tunable in the visible wavelengths

We demonstrate the generation of amplified (~ 8µJ) shaped ultrafast (< 50fs) pulses tunable from 500 to 700nm with bandwidths of up to 50THz. The characterisation of pulse phase and amplitude is provided.
Authors
Tan, HS; Schreiber, E; Warren, WS
MLA Citation
Tan, H. S., et al. “The generation, amplification and characterisation of shaped ultrafast laser pulses, tunable in the visible wavelengths.” Optics Infobase Conference Papers, 2000, pp. 212–14.
URI
https://scholars.duke.edu/individual/pub1529994
Source
scopus
Published In
Optics Infobase Conference Papers
Published Date
Start Page
212
End Page
214

Shaped Pulses

Authors
Warren, WS; Mayr, SM
MLA Citation
Warren, W. S., and S. M. Mayr. “Shaped Pulses.” Emagres, vol. 2007, Jan. 2007. Scopus, doi:10.1002/9780470034590.emrstm0493.
URI
https://scholars.duke.edu/individual/pub1507364
Source
scopus
Published In
Emagres
Volume
2007
Published Date
DOI
10.1002/9780470034590.emrstm0493

Warren, Warren S.: The NMR–Optics Connection

Authors
MLA Citation
Warren, W. S. “Warren, Warren S.: The NMR–Optics Connection.” Emagres, vol. 2007, Jan. 2007. Scopus, doi:10.1002/9780470034590.emrhp0190.
URI
https://scholars.duke.edu/individual/pub1516138
Source
scopus
Published In
Emagres
Volume
2007
Published Date
DOI
10.1002/9780470034590.emrhp0190

„Direct“ <sup>13</sup>C Hyperpolarization of <sup>13</sup>C-Acetate by MicroTesla NMR Signal Amplification by Reversible Exchange (SABRE)

Herein, we demonstrate „direct“ 13C hyperpolarization of 13C-acetate via signal amplification by reversible exchange (SABRE). The standard SABRE homogeneous catalyst [Ir-IMes; [IrCl(COD)(IMes)], (IMes=1,3-bis(2,4,6- trimethylphenyl), imidazole-2-ylidene; COD=cyclooctadiene)] was first activated in the presence of an auxiliary substrate (pyridine) in alcohol. Following addition of sodium 1-13C-acetate, parahydrogen bubbling within a microtesla magnetic field (i.e. under conditions of SABRE in shield enables alignment transfer to heteronuclei, SABRESHEATH) resulted in positive enhancements of up to ≈ 100- fold in the 13C NMR signal compared to thermal equilibrium at 9.4 T. The present results are consistent with a mechanism of „direct“ transfer of spin order from parahydrogen to 13C spins of acetate weakly bound to the catalyst, under conditions of fast exchange with respect to the 13C acetate resonance, but we find that relaxation dynamics at microtesla fields alter the optimal matching from the traditional SABRE-SHEATH picture. Further development of this approach could lead to new ways to rapidly, cheaply, and simply hyperpolarize a broad range of substrates (e.g. metabolites with carboxyl groups) for various applications, including biomedical NMR and MRI of cellular and in vivo metabolism.
Authors
Gemeinhardt, ME; Limbach, MN; Gebhardt, TR; Eriksson, CW; Eriksson, SL; Lindale, JR; Goodson, EA; Warren, WS; Chekmenev, EY; Goodson, BM
MLA Citation
Gemeinhardt, M. E., et al. “„Direct“ 13C Hyperpolarization of 13C-Acetate by MicroTesla NMR Signal Amplification by Reversible Exchange (SABRE).” Advanced Materials, vol. 59, no. 1, Jan. 2020, pp. 426–31. Scopus, doi:10.1002/ANGE.201910506.
URI
https://scholars.duke.edu/individual/pub1532620
Source
scopus
Published In
Advanced Materials (Deerfield Beach, Fla.)
Volume
59
Published Date
Start Page
426
End Page
431
DOI
10.1002/ANGE.201910506