@article {3083, title = {Realization of portable room temperature nanodiamond 13C hyperpolarizer}, year = {Submitted}, author = {A. Ajoy and R. Nazaryan and E. Druga and K. Liu and B. Han and J.T. Oon and M. Gierth and R. Tsang and J.H. Walton and C.A. Meriles and J.A. Reimer and D. Suter and A. Pines} } @article {3170, title = {Dynamics of frequency-swept nuclear spin optical pumping in powdered diamond at low magnetic fields}, journal = {Proceedings of the National Academy of Science}, year = {2019}, month = {01/2019}, abstract = {

A broad effort is underway to improve the sensitivity of NMR through the use of dynamic nuclear polarization. Nitrogen vacancy (NV) centers in diamond offer an appealing platform because these paramagnetic defects can be optically polarized efficiently at room temperature. However, work thus far has been mainly limited to single crystals, because most polarization transfer protocols are sensitive to misalignment between the NV and magnetic field axes. Here we study the spin dynamics of NV\−13C pairs in the simultaneous presence of optical excitation and microwave frequency sweeps at low magnetic fields. We show that a subtle interplay between illumination intensity, frequency sweep rate, and hyperfine coupling strength leads to efficient, sweep-direction-dependent 13C spin polarization over a broad range of orientations of the magnetic field. In particular, our results strongly suggest that finely tuned, moderately coupled nuclear spins are key to the hyperpolarization process, which makes this mechanism distinct from other known dynamic polarization channels. These findings pave the route to applications where powders are intrinsically advantageous, including the hyperpolarization of target fluids in contact with the diamond surface or the use of hyperpolarized particles as contrast agents for in vivo imaging.

}, issn = {0027-8424}, doi = { https://doi.org/10.1073/pnas.1811994116 }, url = {https://www.pnas.org/content/early/2019/01/23/1811994116}, author = {P.R. Zangara and S. Dhomkar and A. Ajoy and K. Liu and R. Nazaryan and D. Pagliero and D. Suter and J. Reimer and A. Pines and C. Meriles} } @article {3531, title = {Rotaxane probes for the detection of hydrogen peroxide by 129Xe hyperCEST NMR}, journal = {Angewandte Chemie International Edition}, year = {2019}, doi = {10.1002/anie.201903045}, url = {https://onlinelibrary.wiley.com/doi/full/10.1002/anie.201903045}, author = {Klass, Sarah H and Truxal, Ashley E and Fiala, T A and Kelly, Joseph and Nguyen, Dang and Finbloom, Joel A and Wemmer, David E and Pines, Alexander and Francis, Matthew B} } @article {2981, title = {Wide dynamic range magnetic field cycler: Harnessing quantum control at low and high fields}, journal = {Review of Scientific Instruments }, volume = {90}, year = {2019}, month = {01/2019}, abstract = {

We describe the construction of a fast field cycling device capable of sweeping a 4-order-of-magnitude range of magnetic fields, from \∼1 mT to 7 T, in under 700 ms, and which is further extendable to a 1 nT-7 T range. Central to this system is a high-speed sample shuttling mechanism between a superconducting magnet and a magnetic shield, with the capability to access arbitrary fields in between with high resolution. Our instrument serves as a versatile platform to harness the inherent dichotomy of spin dynamics on offer at low and high fields\—in particular, the low anisotropy, fast spin manipulation, and rapid entanglement growth at low field as well as the long spin lifetimes, spin specific control, and efficient inductive measurement possible at high fields. Exploiting these complementary capabilities in a single device opens up applications in a host of problems in quantum control, sensing, and information storage, besides in nuclear hyperpolarization, relaxometry, and imaging. In particular, in this paper, we focus on the ability of the device to enable low-field hyperpolarization of 13C nuclei in diamond via optically pumped electronic spins associated with nitrogen vacancy defect centers.

}, doi = {https://doi.org/10.1063/1.5064685}, url = {https://aip.scitation.org/doi/10.1063/1.5064685}, author = {A. Ajoy and X. Lv and E. Druga and K. Liu and B. Safvati and A. Morabe and M. Fenton and R. Nazaryan and S. Patel and T. Sjolander and J. Reimer and D Sakellariou and C. Meriles and A. Pines} } @article {2980, title = {Enhanced dynamic nuclear polarization via swept microwave frequency combs}, journal = {Proc. Natl. Acad. Sci}, year = {2018}, month = {10/2018}, abstract = {

Dynamic nuclear polarization (DNP) has enabled enormous gains in magnetic resonance signals and led to vastly accelerated NMR/MRI imaging and spectroscopy. Unlike conventional cw-techniques, DNP methods that exploit the full electron spectrum are appealing since they allow direct participation of all electrons in the hyperpolarization process. Such methods typically entail sweeps of microwave radiation over the broad electron linewidth to excite DNP but are often inefficient because the sweeps, constrained by adiabaticity requirements, are slow. In this paper, we develop a technique to overcome the DNP bottlenecks set by the slow sweeps, using a swept microwave frequency comb that increases the effective number of polarization transfer events while respecting adiabaticity constraints. This allows a multiplicative gain in DNP enhancement, scaling with the number of comb frequencies and limited only by the hyperfine-mediated electron linewidth. We demonstrate the technique for the optical hyperpolarization of 13C nuclei in powdered microdiamonds at low fields, increasing the DNP enhancement from 30 to 100 measured with respect to the thermal signal at 7T. For low concentrations of broad linewidth electron radicals [e.g., TEMPO ((2,2,6,6-tetramethylpiperidin-1-yl)oxyl)], these multiplicative gains could exceed an order of magnitude.

}, doi = {1807125115}, url = {https://doi.org/10.1073/pnas.1807125115}, author = {Ashok Ajoy and Kristina Liu and Xudong Lv and Raffi Nazaryan and G.Wang and E . Druga and Jeff Reimer and Ditter Suter and C. Ramanathan and C.A Meriles and Alexander Pines} } @article {2979, title = {Orientation independent room-temperature optical 13C hyperpolarization in powdered diamond}, journal = {Science Advances}, volume = {4}, year = {2018}, month = {05/2018}, abstract = {

Dynamic nuclear polarization via contact with electronic spins has emerged as an attractive route to enhance the sensitivity of nuclear magnetic resonance beyond the traditional limits imposed by magnetic field strength and temperature. Among the various alternative implementations, the use of nitrogen vacancy (NV) centers in diamond\—a paramagnetic point defect whose spin can be optically polarized at room temperature\—has attracted widespread attention, but applications have been hampered by the need to align the NV axis with the external magnetic field. We overcome this hurdle through the combined use of continuous optical illumination and a microwave sweep over a broad frequency range. As a proof of principle, we demonstrate our approach using powdered diamond with which we attain bulk 13C spin polarization in excess of 0.25\% under ambient conditions. Remarkably, our technique acts efficiently on diamond crystals of all orientations and polarizes nuclear spins with a sign that depends exclusively on the direction of the microwave sweep. Our work paves the way toward the use of hyperpolarized diamond particles as imaging contrast agents for biosensing and, ultimately, for the hyperpolarization
of nuclear spins in arbitrary liquids brought in contact with their surface.

}, doi = {10.1126/sciadv.aar5492 }, url = {http://advances.sciencemag.org/content/4/5/eaar5492}, author = {Ashok Ajoy and Kristina Liu and Raff Nazaryan and Xudong Lv and Pablo R. Zangara and Benjamin Safvati and Guoqing Wang and Daniel Arnold and Grace Li and Arthur Lin and Priyanka Raghavan and Emanuel Druga and Siddharth Dhomkar and Daniela Pagliero and Jeffrey A. Reimer and Dieter Suter and Carlos A. Meriles and Alexander Pines} } @article {2074, title = {Targeted Molecular Imaging of Cancer Cells using MS2-Based 129Xe NMR}, journal = {Bioconjugate Chemistry}, volume = {27}, year = {2016}, month = {07/2016}, chapter = {1796}, doi = {10.1021/acs.bioconjchem.6b00275}, url = {http://pubs.acs.org/doi/abs/10.1021/acs.bioconjchem.6b00275}, author = {Keunhong Jeong and Chawita Netirojjanakul and Henrik K Munch and Jinny Sun and Joel A Finbloom and David E Wemmer and Alexander Pines and Matthew B Francis} } @article {260, title = {Investigation of antirelaxation coatings for alkali-metal vapor cells using surface science techniques}, journal = {Journal of Chemical Physics}, volume = {133}, year = {2010}, note = {J. Chem. Phys.ISI Document Delivery No.: 667NNTimes Cited: 6Cited Reference Count: 81Seltzer, S. J. Michalak, D. J. Donaldson, M. H. Balabas, M. V. Barber, S. K. Bernasek, S. L. Bouchiat, M. -A. Hexemer, A. Hibberd, A. M. Kimball, D. F. Jackson Jaye, C. Karaulanov, T. Narducci, F. A. Rangwala, S. A. Robinson, H. G. Shmakov, A. K. Voronov, D. L. Yashchuk, V. V. Pines, A. Budker, D.Office of Science, Office of Basic Energy Sciences, Materials Sciences Division and Nuclear Science Division, of the U. S. Department of Energy [DE-AC02-05CH11231]; NSF/DST [PHY-0425916]; Office of Naval Research (ONR) [N0001409WX21049]The authors thank Daniel Fischer, Kristin Schmidt, and Ed Kramer for assistance with the NEXAFS measurements, and Joel Ager, Joshua Wnuk, David Trease, and Gwendal Kervern for helpful discussions and other assistance. S.J.S., D.J.M., M. H. D., A. P., and D. B., the Advanced Light Source, and the DSC, FTIR, and AFM studies were supported by the Director, Office of Science, Office of Basic Energy Sciences, Materials Sciences Division and Nuclear Science Division, of the U. S. Department of Energy under Contract No. DE-AC02-05CH11231 at Lawrence Berkeley National Laboratory. Other parts of this work were funded by the NSF/DST under Grant No. PHY-0425916 for U.S.-India cooperative research, by an Office of Naval Research (ONR) MURI grant, and by ONR under Grant No. N0001409WX21049.AMER INST PHYSICSMELVILLE}, month = {October 11, 2010}, pages = {144703}, type = {Article}, chapter = {144703}, abstract = {

Many technologies based on cells containing alkali-metal atomic vapor benefit from the use of antirelaxation surface coatings in order to preserve atomic spin polarization. In particular, paraffin has been used for this purpose for several decades and has been demonstrated to allow an atom to experience up to 10 000 collisions with the walls of its container without depolarizing, but the details of its operation remain poorly understood. We apply modern surface and bulk techniques to the study of paraffin coatings in order to characterize the properties that enable the effective preservation of alkali spin polarization. These methods include Fourier transform infrared spectroscopy, differential scanning calorimetry, atomic force microscopy, near-edge x-ray absorption fine structure spectroscopy, and x-ray photoelectron spectroscopy. We also compare the light-induced atomic desorption yields of several different paraffin materials. Experimental results include the determination that crystallinity of the coating material is unnecessary, and the detection of CvC double bonds present within a particular class of effective paraffin coatings. Further study should lead to the development of more robust paraffin antirelaxation coatings, as well as the design and synthesis of new classes of coating materials. (C) 2010 American Institute of Physics. [doi:10.1063/1.3489922]

}, keywords = {SPECTROSCOPY}, isbn = {0021-9606}, doi = {10.1063/1.3489922}, url = {http://link.aip.org/link/doi/10.1063/1.3489922}, author = {Seltzer, S. J. and Michalak, D. J. and Donaldson, M. H. and Balabas, M. V. and Barber, S. K. and Bernasek, S. L. and Bouchiat, M. A. and Hexemer, A. and Hibberd, A. M. and Kimball, D. F. J. and Jaye, C. and Karaulanov, T. and Narducci, F. A. and Rangwala, S. A. and Robinson, H. G. and Shmakov, A. K. and Voronov, D. L. and Yashchuk, V. V. and Pines, A. and Budker, D.} } @article {300, title = {Solid-state NMR structural studies of the fibril form of a mutant mouse prion peptide PrP89-143(P101L)}, journal = {Solid State Nuclear Magnetic Resonance}, volume = {29}, year = {2006}, note = {Solid State Nucl Mag999VATimes Cited:22Cited References Count:34}, month = {Feb}, pages = {183-190}, abstract = {

The peptide fragment 89-143 of the prion protein (carrying a P101L mutation) is biologically active in transgenic mice when in a fibrillar form. Injection of these fibrils into transgenic mice (expressing full length PrP with the P101L mutation) induces a neurodegenerative prion disease (Kaneko et al., J. Mol. Biol. 295 (2000) 997). Here we present solid-state NMR studies of PrP89-143(P101L) fibrils, probing the conformation of residues in the hydrophobic segment 112-124 with chemical shifts. The conformations of glycine residues were analyzed using doubly C-13 = 0 labeled peptides by two-dimensional (2D) double-quantum correlation, and double-quantum filtered dephasing distance measurements. MQ-NMR experiments were carried out to probe the relative alignment of the individual peptides fibrils. These NMR studies indicate that the 112-124 segment adopts an extended beta-sheet conformation, though not in a parallel, in register alignment. There is evidence for conformational variability at Gly 113. DQ correlation experiments provide useful information in regions with conformational heterogeneity. (c) 2005 Elsevier Inc. All rights reserved.

}, keywords = {identification}, isbn = {0926-2040}, doi = {Doi 10.1016/J.Ssnmr.2005.09.017}, url = {://WOS:000234417500020}, author = {Lim, K. H. and Nguyen, T. N. and Damo, S. M. and Mazur, T. and Ball, H. L. and Prusiner, S. B. and Pines, A. and Wemmer, D. E.} } @article {312, title = {High-resolution nuclear magnetic resonance spectroscopy of biological tissues using projected magic angle spinning}, journal = {Magnetic Resonance in Medicine}, volume = {54}, year = {2005}, note = {Magnet Reson Med949DSTimes Cited:2Cited References Count:28}, month = {Aug}, pages = {253-257}, abstract = {

High-resolution NMR spectra of materials subject to anisotropic broadening are usually obtained by rotating the sample about the magic angle, which is 54.7 degrees to the static magnetic field. In projected magic angle spinning (p-MAS), the sample is spun about two angles, neither of which is the magic angle. This provides a method of obtaining isotropic spectra while spinning at shallow angles. The p-MAS experiment may be used in situations where spinning the sample at the magic angle is not possible due to geometric or other constraints, allowing the choice of spinning angle to be determined by factors such as the shape of the sample, rather than by the spin physics. The application of this technique to bovine tissue samples is demonstrated as a proof of principle for future biological or medical applications.

}, keywords = {field}, isbn = {0740-3194}, doi = {Doi 10.1002/Mrm.20585}, url = {://WOS:000230765700001}, author = {Martin, R. W. and Jachmann, R. C. and Sakellariou, D. and Nielsen, U. G. and Pines, A.} } @article {360, title = {Sensitivity enhancement in multiple-quantum NMR experiments with CPMG detection}, journal = {Journal of Magnetic Resonance}, volume = {157}, year = {2002}, note = {J Magn Reson589DHTimes Cited:12Cited References Count:12}, month = {Jul}, pages = {160-162}, abstract = {

We present a modified multiple-quantum (MQ) experiment, which implements the Carr-Purcell-Meiboom-Gill (CPMG) detection scheme in the static MQ NMR experiment proposed by W. S. Warren et al. (1980, J. Chem. Phys. 73, 2084-2099) and exploited further by O. N. Antzutkin and R. Tycko (1999, J. Chem. Phys. 110, 2749-2752). It is demonstrated that a significant enhancement in the sensitivity can be achieved by acquiring echo trains in the MQ experiments for static powder samples. The modified scheme employing the CPMG detection was superior to the original MQ experiment, in particular for the carbonyl carbon with a very large chemical shift anisotropy. (C) 2002 Elsevier Science (USA).

}, keywords = {dynamics}, isbn = {1090-7807}, doi = {Doi 10.1006/Jmre.2002.2578}, url = {://WOS:000177742400019}, author = {Lim, K. H. and Nguyen, T. and Mazur, T. and Wemmer, D. E. and Pines, A.} } @article {420, title = {In vivo NMR and MRI using injection delivery of laser-polarized xenon}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {94}, year = {1997}, note = {P Natl Acad Sci USAYn574Times Cited:55Cited References Count:39}, month = {Dec 23}, pages = {14725-14729}, abstract = {

Because xenon NMR is highly sensitive to the local environment, laser-polarized xenon could be a unique probe of living tissues. Realization of clinical and medical science applications beyond lung airspace imaging requires methods of efficient delivery of laser-polarized xenon to tissues, because of the short spin-lattice relaxation times and relatively low concentrations of xenon attainable in the body. Preliminary results from the application of a polarized xenon injection technique for in vivo Xe-129 NMR/MRI are extrapolated along with a simple model of xenon transit to show that the peak local concentration of polarized xenon delivered to tissues by injection may exceed that delivered by respiration by severalfold.

}, keywords = {humans}, isbn = {0027-8424}, doi = {Doi 10.1073/Pnas.94.26.14725}, url = {://WOS:000071182800090}, author = {Goodson, B. M. and Song, Y. Q. and Taylor, R. E. and Schepkin, V. D. and Brennan, K. M. and Chingas, G. C. and Budinger, T. F. and Navon, G. and Pines, A.} } @article {409, title = {Selective enhancement of NMR signals for alpha-cyclodextrin with laser-polarized xenon}, journal = {Angewandte Chemie-International Edition in English}, volume = {36}, year = {1997}, note = {Angew Chem Int EditYh944Times Cited:48Cited References Count:29}, month = {Nov 14}, pages = {2368-2370}, keywords = {solids}, isbn = {0570-0833}, doi = {Doi 10.1002/Anie.199723681}, url = {://WOS:A1997YH94400025}, author = {Song, Y. Q. and Goodson, B. M. and Taylor, R. E. and Laws, D. D. and Navon, G. and Pines, A.} } @article {426, title = {Enhancement of solution NMR and MRI with laser-polarized xenon}, journal = {Science}, volume = {271}, year = {1996}, note = {ScienceUc778Times Cited:230Cited References Count:41}, month = {Mar 29}, pages = {1848-1851}, abstract = {

Optical pumping with laser light can be used to polarize the nuclear spins of gaseous xenon-129. When hyperpolarized xenon-129 is dissolved in liquids, a time-dependent departure of the proton spin polarization from its thermal equilibrium is observed, The variation of the magnetization is an unexpected manifestation of the nuclear Overhauser effect, a consequence of cross-relaxation between the spins of solution protons and dissolved xenon-129. Time-resolved magnetic resonance images of both nuclei in solution show that the proton magnetization is selectively perturbed in regions containing spin-polarized xenon-129. This effect could find use in nuclear magnetic resonance spectroscopy of surfaces and proteins and in magnetic resonance imaging.

}, keywords = {resonance}, isbn = {0036-8075}, doi = {Doi 10.1126/Science.271.5257.1848}, url = {://WOS:A1996UC77800041}, author = {Navon, G. and Song, Y. Q. and Room, T. and Appelt, S. and Taylor, R. E. and Pines, A.} } @article {433, title = {NMR of laser-polarized xenon in human blood}, journal = {Proceedings of the National Academy of Sciences of the United States of America}, volume = {93}, year = {1996}, note = {P Natl Acad Sci USAVt054Times Cited:92Cited References Count:27}, month = {Nov 12}, pages = {12932-12936}, abstract = {

By means of optical pumping with laser light it is possible to enhance the nuclear spin polarization of gaseous xenon by four to five orders of magnitude, The enhanced polarization has allowed advances in nuclear magnetic resonance (NMR) spectroscopy and magnetic resonance imaging (MRI), including polarization transfer to molecules and imaging of lungs and other void spaces, A critical issue for such applications is the delivery of xenon to the sample while maintaining the polarization, Described herein is an efficient method for the introduction of laser-polarized xenon into systems of biological and medical interest for the purpose of obtaining highly enhanced NMR/MRI signals. Using this method, we have made the first observation of the time-resolved process of xenon penetrating the red blood cells in fresh human blood-the xenon residence time constant in the red blood cells was measured to be 20.4+/-2 ms. The potential of certain biologically compatible solvents for delivery of laser-polarized xenon to tissues for NMR/MRI is discussed in light of their respective relaxation and partitioning properties.

}, keywords = {gas}, isbn = {0027-8424}, doi = {Doi 10.1073/Pnas.93.23.12932}, url = {://WOS:A1996VT05400048}, author = {Bifone, A. and Song, Y. Q. and Seydoux, R. and Taylor, R. E. and Goodson, B. M. and Pietrass, T. and Budinger, T. F. and Navon, G. and Pines, A.} } @inbook {436, title = {Synthetic Peptides Model α - Helix - β - Sheet Conformational Changes in the Prion Protien}, booktitle = {Peptides: Chemistry, Structure and Biology}, year = {1996}, pages = {468-470}, publisher = {Mayflower Scientific Ltd.}, organization = {Mayflower Scientific Ltd.}, author = {Baldwin, M.A. and Zhang, H. and Bekker, T. and Zhou, S. and Nguyen, J. and Kolbert, A.C. and Heller, J. and James, T.L. and Wemmer, D.E. and Pines, A. and Cohen, F.E. and Prusiner, S.B.}, editor = {Hidges, Pravin T.P Kaumaya and Robert S.} } @article {444, title = {Low-Power Decoupling Sequences for High-Resolution Chemical-Shift and Local-Field Nmr-Spectra of Liquid-Crystals}, journal = {Journal of Magnetic Resonance Series A}, volume = {113}, year = {1995}, note = {J Magn Reson Ser AQw158Times Cited:11Cited References Count:29}, month = {Apr}, pages = {169-176}, abstract = {

Various new and well-established multiple-pulse sequences that provide homonuclear dipolar decoupling are compared on a high-resolution spectrometer/probe configuration using low RF-irradiation powers. Proton-proton decoupled carbon-13 spectra of singly C-13-labeled benzene dissolved in a nematic liquid crystal and of the liquid crystal 152 are presented. Two classes of multiple-pulse sequences are studied that produce either broadband decoupled carbon spectra or separated local-held spectra. Several new approaches for the design of windowless sequences are demonstrated to be valuable in these heteronuclear experiments. They include implementations of the iterative MLEV scheme and the use of 270 degrees pulses. Furthermore, noncyclic propagators have been found that exhibit advantages over closely related cyclic analogues in both classes of decoupling sequences. (C) 1995 Academic Press, Inc.

}, keywords = {dipolar}, isbn = {1064-1858}, doi = {Doi 10.1006/Jmra.1995.1077}, url = {://WOS:A1995QW15800005}, author = {Nanz, D. and Ernst, M. and Hong, M. and Ziegeweid, M. A. and Schmidt-Rohr, K. and Pines, A.} } @article {458, title = {Nmr Measurement of Resolved Heteronuclear Dipole Couplings in Liquid-Crystals and Lipids}, journal = {Journal of Physical Chemistry}, volume = {98}, year = {1994}, note = {J Phys Chem-UsNw531Times Cited:68Cited References Count:25}, month = {Jul 7}, pages = {6668-6670}, abstract = {

Simplified nuclear magnetic resonance (NMR) spectra of heteronuclear dipolar couplings for molecules in an anisotropic environment, such as liquid crystals and lipids, are obtained by proton-detected local-field spectroscopy. The distance-dependent dipolar interactions between spins of magnetically active nuclei can be determined directly from the spectrum because many-body effects that complicate conventional dipolar NMR spectra are avoided by selectively probing local fields produced by rare spins at the location of abundant spins. We employ the technique to resolve the carbon-proton dipolar couplings of benzene dissolved in a nematic liquid crystal and to measure phosphorus-proton couplings in lecithin in the L(alpha) phase to obtain constraints on the phosphocholine headgroup structure.

}, keywords = {solids}, isbn = {0022-3654}, doi = {Doi 10.1021/J100078a002}, url = {://WOS:A1994NW53100002}, author = {Schmidt-Rohr, K. and Nanz, D. and Emsley, L. and Pines, A.} } @article {551, title = {Nuclear Magnetic-Resonance with Dc Squid Preamplifiers}, journal = {Ieee Transactions on Magnetics}, volume = {25}, year = {1989}, note = {Ieee T MagnT6706Times Cited:21Cited References Count:23}, month = {Mar}, pages = {1193-1199}, isbn = {0018-9464}, doi = {Doi 10.1109/20.92510}, url = {://WOS:A1989T670600113}, author = {Fan, N. Q. and Heaney, M. B. and Clarke, J. and Newitt, D. and Wald, L. L. and Hahn, E. L. and Bielecki, A. and Pines, A.} }