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:

Agilent Direct Drive 9.4T MRS/MRI Console

Administered By
Radiology
Awarded By
National Institutes of Health
Role
Major User
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:

15N-Azides as practical and effective tags for developing long-lived hyperpolarized agents.

Azide moieties, unique linear species containing three nitrogen atoms, represent an attractive class of molecular tag for hyperpolarized magnetic resonance imaging (HP-MRI). Here we demonstrate (15N)3-azide-containing molecules exhibit long-lasting hyperpolarization lifetimes up to 9.8 min at 1 T with remarkably high polarization levels up to 11.6% in water, thus establishing (15N)3-azide as a powerful spin storage for hyperpolarization. A single (15N)-labeled azide has also been examined as an effective alternative tag with long-lived hyperpolarization. A variety of biologically important molecules are studied in this work, including choline, glucose, amino acid, and drug derivatives, demonstrating great potential of 15N-labeled azides as universal hyperpolarized tags for nuclear magnetic resonance imaging applications.
Authors
MLA Citation
Bae, Junu, et al. “15N-Azides as practical and effective tags for developing long-lived hyperpolarized agents.Chem Sci, vol. 12, no. 42, Nov. 2021, pp. 14309–15. Pubmed, doi:10.1039/d1sc04647k.
URI
https://scholars.duke.edu/individual/pub1500492
PMID
34760217
Source
pubmed
Published In
Chem. Sci.
Volume
12
Published Date
Start Page
14309
End Page
14315
DOI
10.1039/d1sc04647k

Visualization of vermilion degradation using pump-probe microscopy

Authors
Yu, J; Warren, WS; Fischer, MC
MLA Citation
Yu, Jin, et al. “Visualization of vermilion degradation using pump-probe microscopy.” Science Advances, vol. 5, no. 6, American Association for the Advancement of Science (AAAS), June 2019. Crossref, doi:10.1126/sciadv.aaw3136.
URI
https://scholars.duke.edu/individual/pub1395925
PMID
31245540
Source
crossref
Published In
Science Advances
Volume
5
Published Date
DOI
10.1126/sciadv.aaw3136

Low-cost measurement of face mask efficacy for filtering expelled droplets during speech.

Mandates for mask use in public during the recent coronavirus disease 2019 (COVID-19) pandemic, worsened by global shortage of commercial supplies, have led to widespread use of homemade masks and mask alternatives. It is assumed that wearing such masks reduces the likelihood for an infected person to spread the disease, but many of these mask designs have not been tested in practice. We have demonstrated a simple optical measurement method to evaluate the efficacy of masks to reduce the transmission of respiratory droplets during regular speech. In proof-of-principle studies, we compared a variety of commonly available mask types and observed that some mask types approach the performance of standard surgical masks, while some mask alternatives, such as neck gaiters or bandanas, offer very little protection. Our measurement setup is inexpensive and can be built and operated by nonexperts, allowing for rapid evaluation of mask performance during speech, sneezing, or coughing.
Authors
Fischer, EP; Fischer, MC; Grass, D; Henrion, I; Warren, WS; Westman, E
MLA Citation
Fischer, Emma P., et al. “Low-cost measurement of face mask efficacy for filtering expelled droplets during speech.Sci Adv, vol. 6, no. 36, Sept. 2020. Pubmed, doi:10.1126/sciadv.abd3083.
URI
https://scholars.duke.edu/individual/pub1459166
PMID
32917603
Source
pubmed
Published In
Science Advances
Volume
6
Published Date
DOI
10.1126/sciadv.abd3083

Infinite-order perturbative treatment for quantum evolution with exchange.

Many important applications in biochemistry, materials science, and catalysis sit squarely at the interface between quantum and statistical mechanics: Coherent evolution is interrupted by discrete events, such as binding of a substrate or isomerization. Theoretical models for such dynamics usually truncate the incorporation of these events to the linear response limit, thus requiring small step sizes. Here, we completely reassess the foundations of chemical exchange models and redesign a master equation treatment for exchange accurate to infinite order in perturbation theory. The net result is an astonishingly simple correction to the traditional picture, which vastly improves convergence with no increased computational cost. We demonstrate that this approach accurately and efficiently extracts physical parameters from complex experimental data, such as coherent hyperpolarization dynamics in magnetic resonance, and is applicable to a wide range of other systems.
Authors
Lindale, JR; Eriksson, SL; Tanner, CPN; Warren, WS
MLA Citation
Lindale, Jacob R., et al. “Infinite-order perturbative treatment for quantum evolution with exchange.Science Advances, vol. 6, no. 32, Aug. 2020, p. eabb6874. Epmc, doi:10.1126/sciadv.abb6874.
URI
https://scholars.duke.edu/individual/pub1456748
PMID
32821841
Source
epmc
Published In
Science Advances
Volume
6
Published Date
Start Page
eabb6874
DOI
10.1126/sciadv.abb6874

Unraveling the molecular nature of melanin changes in metastatic cancer

Authors
Ju, K-Y; Degan, S; Fischer, MC; Zhou, KC
MLA Citation
Ju, Kuk-Youn, et al. “Unraveling the molecular nature of melanin changes in metastatic cancer.” Journal of Biomedical Optics, vol. 24, no. 05, SPIE-Intl Soc Optical Eng, Apr. 2019, pp. 1–1. Crossref, doi:10.1117/1.jbo.24.5.051414.
URI
https://scholars.duke.edu/individual/pub1381256
PMID
30977334
Source
crossref
Published In
Journal of Biomedical Optics
Volume
24
Published Date
Start Page
1
End Page
1
DOI
10.1117/1.jbo.24.5.051414