MATERIALS

CROSS-REFERENCE

[001] The present application claims priority to U.S. Provisional Patent Application No. 63/375,390, entitled “SYSTEMS AND METHODS FOR GENERATION OF HYPERPOLARIZED MATERIALS,” filed on September 13, 2022 and U.S. Provisional Patent Application No. 63/460,629, entitled “SYSTEMS AND METHODS FOR GENERATION OF HYPERPOLARIZED MATERIALS,” filed on April 20, 2023, each of which is incorporated herein by reference in its entirety for all purposes.

TECHNICAL FIELD

[002] The disclosed embodiments generally relate to generation of hyperpolarized materials for use in nuclear magnetic resonance (NMR), magnetic resonance imaging (MRI), or similar applications.

BACKGROUND

[003] Nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) are technologies with vital applications in chemistry, biology, and medical imaging. Despite these successes, it is recognized that magnetic resonance applications may often have limitations due to the minute nuclear polarization of analytes (typically on the order of 10' ⁵ ) at thermal equilibrium. This minute nuclear polarization can result in limited sensitivity in comparison to other analytic techniques such as mass spectrometry. [004] Increasing nuclear spin polarization beyond its thermal equilibrium value can greatly improve magnetic resonance sensitivity. Nuclear spin polarization can be increased using known techniques like dynamic nuclear polarization (DNP), parahydrogen induced polarization (PHIP), PHIP-sidearm hydrogenation (PHIP-SAH), PHIP relayed via proton exchange (PHIP-X), and PHIP nuclear Overhauser effect system (PHIPNOESYS). Using such techniques, the nuclear spin polarization of a material can be increased by factor that often exceeds 100 and may in some cases exceed 10,000 or more. The enhanced nuclear spin polarization can result in a proportional increase in the NMR/MRI signal.

[005] These techniques can achieve high degrees of polarization at moderate concentrations, making them attractive approaches for various applications. For instance, polarized molecules prepared via PHIP or PHIP-SAH can be used directly in NMR or MRI experiments. Alternatively, the polarized molecules can be used as sources for transferring polarization to other molecules via procedures such as PHIPNOESYS and PHIP-X. However, when the polarized molecules are present at high concentrations, a strong demagnetization field originating from the dipolar field associated with the magnetization of polarized molecules in the sample can interfere with polarization transfer, limiting the achievable product of polarization and concentration (i.e., molar polarization). Thus, PHIP, PHIP-SAH, PHIPNOESYS, and PHIP-X have thus far been limited in the achievable molar polarization.

SUMMARY

[006] In accordance with the present disclosure, a solution comprising a hyperpolarized molecule dissolved therein can be obtained. The hyperpolarized molecule can comprise at least one nucleus having a molar polarization of at least 50 millimolar (mM). Prior to obtaining the solution, a nuclear spin hyperpolarization protocol can be performed on the hyperpolarized molecule to thereby impart the molar polarization to the at least one nucleus. The nuclear spin hyperpolarization procedure can comprise: obtaining a solution comprising a derivative of the hyperpolarized molecule, the derivative comprising at least one unsaturated carbon-carbon double bond or unsaturated carbon-carbon triple bond and having the form R1 — C = C — R2 or R1 — C = C — R2, wherein R1 and R2 comprise sidechains; hydrogenating the double bond or triple bond with parahydrogen to form a parahydrogenated derivative of the hyperpolarized molecule, the parahydrogenated derivative having the form R1 — CH* — CH* — R2 or R1 — CH* = CH* — R2, wherein H* denotes a parahydrogen-derived hydrogen atom added across the double bond or triple bond; and applying a polarization transfer waveform to transfer nuclear spin order from at least one of the parahydrogen-derived hydrogen atoms to the at least one nucleus, thereby imparting a nuclear spin hyperpolarization to the at least one nucleus. The polarization transfer waveform can be configured to suppress a dipolar field associated with magnetization that is generated during a buildup of the nuclear spin hyperpolarization. The polarization transfer waveform can comprise a dipolar decoupling sequence. The polarization transfer waveform can further comprise a concatenated driving field based on a parameter sweep. The parameter sweep can further comprise a transverse magnetic field (B ₁ ) sweep. For instance, the polarization transfer waveform can comprise a B ₁ sweep at the Lee-Goldburg frame. The polarization transfer waveform can comprise a pulse sequence selected from the group consisting of: polarizing MREV- 8, polarizing BLEW- 12, and polarizing BR-24. The hyperpolarized molecule can be used in a PHIP, PHIP-SAH, PHIPNOESYS, or PHIP-X experiment. The polarization transfer waveform can permit molar polarizations that would otherwise be unobtainable due to buildup of magnetization during the polarization procedure. [007] It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the disclosed embodiments, as claimed.

BRIEF DESCRIPTION OF THE DRAWINGS

[008] The accompanying drawings, which comprise a part of this specification, illustrate several embodiments and, together with the description, serve to explain the principles and features of the disclosed embodiments. In the drawings:

[009] FIG. 1 depicts an exemplary method for generating high molar polarization in a hyperpolarized molecule via a PHIP nuclear spin hyperpolarization protocol, in accordance with disclosed embodiments.

[010] FIG. 2 depicts an exemplary method 200 for generating high molar polarization in a hyperpolarized molecule via a PHIP- S AH nuclear spin hyperpolarization protocol, in accordance with disclosed embodiments.

[011] FIG. 3 shows exemplary numerical simulations of molar polarization versus concentration for the polarizing MREV-8, polarizing BLEW-12, polarizing BR-24, and transverse magnetic field sweep at Lee-Goldburg frame pulse sequences for (l- ¹³ C,de)-dimethyl maleate, in accordance with disclosed embodiments.

[012] FIG. 4 shows exemplary numerical simulations of molar polarization versus concentration for the polarizing MREV-8, polarizing BLEW-12, polarizing BR-24, and transverse magnetic field sweep at Lee-Goldburg frame pulse sequences for (l- ¹³ C)-fumaric acid, in accordance with disclosed embodiments.

[013] FIG. 5 shows exemplary numerical simulations of molar polarization versus concentration for the polarizing MREV-8, polarizing BLEW-12, polarizing BR-24, and transverse magnetic field sweep at Lee-Goldburg frame pulse sequences for (l,2-d2)-ethyl acetate, in accordance with disclosed embodiments.

[014] FIG. 6 shows exemplary molar polarizations of hyperpolarized (l- ¹³ C,d6)-dimethyl maleate as a function of concentration, in accordance with disclosed embodiments.

[015] FIG. 7 shows exemplary spin polarizations of hyperpolarized (l- ¹³ C,de)-dimethyl maleate as a function of effective angle of Lee-Goldburg decoupling, in accordance with disclosed embodiments.

[016] FIG. 8 shows an exemplary hyperpolarized ³ H spectrum of l- ¹³ C-de-dimethyl maleate acquired at 9.41 T magnetic field after polarization transfer using the polarizing MREV-8 sequence, in accordance with disclosed embodiments.

DETAILED DESCRIPTION

[017] Reference will now be made in detail to exemplary embodiments, discussed with regards to the accompanying drawings. In some instances, the same reference numbers will be used throughout the drawings and the following description to refer to the same or like parts. Unless otherwise defined, technical and/or scientific terms have the meaning commonly understood by one of ordinary skill in the art. The disclosed embodiments are described in sufficient detail to enable those skilled in the art to practice the disclosed embodiments. It is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the disclosed embodiments. Thus, the materials, methods, and examples are illustrative only and are not intended to be necessarily limiting.

[018] NMR and MRI can be used in a wide variety of applications including, but not limited to, the determination of chemical structures in synthetic intermediates, the determination of the atomic-level structure and dynamics in proteins and nucleic acids, minimally invasive imaging of biological tissues or organisms, and even metabolic analyses of biological tissues or organisms. However, NMR and MRI can have limited sensitivity due to a combination of the minute size of nuclear magnetic moments and the correspondingly small polarization at thermal equilibrium. This limited sensitivity can prevent the use of NMR and MRI in some applications and can render other applications of NMR and MRI impractically time- or material-consuming.

[019] NMR and MRI sensitivity can be increased through the use of higher magnetic fields and optimized detection systems. However, an alternative approach is to increase NMR and MRI sensitivity by increasing nuclear spin polarization to levels significantly greater than thermal equilibrium. Such hyperpolarization techniques can often increase the NMR and MRI sensitivity by a factor that is significantly greater than increasing the magnetic field or using optimized detection systems.

[020] Nuclear spin polarization can be increased using a variety of techniques, including dynamic nuclear polarization (DNP), parahydrogen-induced polarization (PHIP), PHIP-sidearm hydrolysis (PHIP-SAH), signal amplification by reversible exchange (SABRE), PHIP relayed via proton exchange (PHIP-X), PHIP nuclear Overhauser effect system (PHIPNOESYS), spin-exchange optical pumping (SEOP), optically initialized electron triplet states (also referred to as photoexcited triplet states, PETS), and other suitable methods. Among these techniques, parahydrogen-based methods such as PHIP, PHIP-SAH, PHIP-X, and PHIPNOESYS are especially promising, as they can be performed at high throughput using relatively low-cost equipment.

[021] For instance, recent work in NMR and MRI has demonstrated that NMR and MRI signals associated with a variety of biorelevant imaging agents can be enhanced by many orders of magnitude using PHIP or PHIP-SAH. Such drastic signal enhancement allows spectroscopic analysis of the biorelevant imaging agent as it is metabolized by various tissues at different locations within a body. Analysis of the metabolic information determined by such spectroscopic imaging may allow non-invasive determination of a health state of tissue within a body. For example, abnormal metabolism of the biorelevant imaging agent may be indicative of a disease such as cancer at some location in the body.

[022] In PHIP and PHIP-SAH, a derivative (e.g., a precursor) of a molecule of interest is reacted with parahydrogen to form a parahydrogenated form of the derivative. Spin order is then transferred from the protons added via the parahydrogenation reaction to a nucleus of interest (such as a carbon- 13 nucleus) contained within the molecule of interest. In PHIP, the parahydrogenated form of the derivative is chemically identical to the molecule of interest and distinguished from the molecule of interest only by the spin order derived from the parahydrogenation reaction. In PHIP-SAH, the parahydrogenated form of the derivative is cleaved (e.g., hydrolyzed) to yield the hyperpolarized molecule of interest. In SABRE, the molecule of interest itself forms a coordination complex with a polarization transfer catalyst and parahydrogen. Spin order is then transferred from the parahydrogen to a nucleus of interest within the molecule of interest via the coordination complex. The molecule of interest is then optionally purified and used in an NMR or MRI procedure. PHIP-X and PHIPNOESYS utilize PHIP or PHIP-SAH to generate a hyperpolarized material (e.g., the source compound) and transfers polarization from the source compound to the material used in NMR spectroscopy (e.g., the target compound, target molecule, or molecule of interest). In PHIP-X, the transfer or polarization from source compound to target compound proceeds via proton exchange from source compound to target compound. Subsequently, polarization may be transferred internally within the target compound through the intramolecular nuclear Overhauser effect (NOE). In PHIPNOESYS, the transfer of polarization from source compound to target compound proceeds via the intermolecular NOE. PHIPNOESYS has been shown to increase signals in NMR spectroscopy by up to a factor of nearly 2,000, allowing for application of NMR spectroscopy at significantly reduced concentrations than would otherwise be achievable.

[023] The ultimate aim of hyperpolarization techniques such as PHIP, PHIP-SAH, PHIPNOESYS, and PHIP-X is to create high concentrations of highly polarized molecules. However, when the polarized molecules are present at high concentrations, a strong demagnetization field originating from the polarized molecules in the sample can interfere with polarization transfer, limiting the achievable product of polarization and concentration (i.e., molar polarization). Thus, PHIP, PHIP-SAH, PHIPNOESYS, and PHIP-X have thus far been limited in the achievable molar polarization. Accordingly, there is a need for systems and methods that cancel out the effects of the large demagnetization field generated when polarized molecules are present at high concentrations and to allow the generation of large molar polarizations.

[024] As described herein, the challenge posed by the strong demagnetization fields discussed above can be mitigated using novel pulse sequences that cancel out the effects of the demagnetization field. The systems and methods described herein enable efficient polarization transfer even at high concentrations, without limitations on the molar polarization. Such new pulse sequences open up exciting opportunities for using hyperpolarization techniques in a wide range of applications, including MRI and drug discovery, and has potential implications for molecular imaging, materials science, and beyond.

[025] The disclosed embodiments generate hyperpolarized molecules dissolved in solutions. The hyperpolarized molecules generally comprise at least one nucleus that has a large molar polarization. The large molar polarization is generated by applying a polarization transfer waveform during buildup of polarization on the at least one nucleus. The polarization transfer waveform is generally configured to suppress a dipolar field associated with magnetization that is generated during the buildup of the polarization. For instance, the polarization transfer waveform may comprise any one or more of a dipolar decoupling sequence, transverse magnetic field sweep at, for instance, the Lee-Goldburg frame, a polarizing MREV-8 pulse sequence, a polarizing BLEW-12 pulse sequence, a polarizing BR-24 pulse sequence, and the like. Following the polarization transfer waveform, the at least one nucleus may be associated with a relatively high molar polarization. The hyperpolarized molecule may then be used by an end user, such as a hospital or clinic, in an NMR or MRI experiment.

Hyperpolarization and parahydrogen

[026] As used in the present disclosure, “polarization” refers to an imbalance in electron or nuclear spin orientations. In some embodiments, polarization can be the normalized, approximate difference in the number of spins in a first direction minus a number of spins in the opposite direction. As a non-limiting example, given 200,000 nuclear spins, a polarization of 2% can correspond to 102,000 spins in the first direction and 98,000 in the opposite direction. In some embodiments, “hyperpolarization” can include polarization of a species (e.g., nuclear, election, or the like) in excess of typical polarization levels for that species observed at thermal equilibrium subject to exposure to a specified magnetic field. As a non-limiting example, a sample in a 1 tesla (T) magnetic field at thermal equilibrium, with nuclear spin polarization in excess of 0.000341% can be hyperpolarized to have a nuclear spin polarization substantially higher (e.g., at least one or more orders of magnitude higher) than the 0.000341% thermal equilibrium polarization. As an additional nonlimiting example, a sample in a 3 T magnetic field at thermal equilibrium, with ¹³ C spin polarization in excess of 0.000257% can be hyperpolarized. As a further nonlimiting example, a sample in a 3 T magnetic field at thermal equilibrium, with ¹⁵ N spin polarization in excess of 0.000103% can be hyperpolarized.

[027] As used in the present disclosure, “hyperpolarization” describes a condition in which an absolute value of a difference between a population of spin states (e.g., nuclear spin states, proton spin states, or the like) being in one state (e.g., spin up) and a population of a spin states being in another state (e.g., spin down) exceeds the absolute value of the corresponding difference at thermal equilibrium.

[028] Parahydrogen can be used as a source of polarization, consistent with disclosed embodiments. Parahydrogen, as described herein, is a form of molecular hydrogen in which the two proton spins are in the singlet state. The disclosed embodiments are not limited to a particular method of generating parahydrogen. Parahydrogen may be formed in a gas form or in a liquid form. In some embodiments, parahydrogen is generated in gas form by flowing hydrogen gas at low temperature through a chamber with a catalyst (e.g., iron oxide or another suitable catalyst). The hydrogen gas can contain both parahydrogen and orthohydrogen. The low temperature can bring the hydrogen gas to thermodynamic equilibrium in the chamber, increasing the population of parahydrogen.

[029] As used in the present disclosure, a population difference between two spin states is the difference between the population of the two spin states divided by the total population of the two spin states. A population difference may be expressed as a fractional population difference or a percentage population difference. In some embodiments, the fractional population difference is at least about 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or more, at most about 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, or less, or within a range defined by any two of the preceding values.

[030] Hydrogen gas can exhibit a population difference between proton spin states which greatly exceeds the population difference between proton spin states at thermal equilibrium. Hydrogen gas containing a high concentration of parahydrogen can have a large population difference between the singlet spin state and any of the triplet spin states. In the case of Izllz2 order, there is a large population difference, for example, between the spin state | T>| J,> and the spin state |T>|T>. The population difference in proton spin states can be at least about 0.1 (e.g., a 10% difference in spin states or 55 % of the parahydrogen molecules in a sample being in the singlet state and 45% in the triplet state), 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, or more, at most about 0.9, 0.8, 0.7, 0.6, 0.5, 0.4, 0.3, 0.2, 0.1, or less, or within a range defined by any two of the preceding values.

[031] As used in the present disclosure, “molar polarization” refers to the product of polarization and concentration of a particular nucleus. As used in the present disclosure, molar polarization is typically quoted in concentration units, such as millimolar (mM) units and is obtained by multiplying the concentration of a particular nucleus by its polarization expressed as a fractional value. For instance, a molecule may be present in solution at a concentration of 100 mM. The molecule may comprises a single carbon- 13 nucleus having a nuclear spin polarization of 40% (i.e., a polarization of 0.4). In the present disclosure, such a molecule would have a carbon- 13 molar polarization of 100 mM times 0.4 = 40 mM. Similarly, a molecule present in solution at a concentration of 100 mM, comprising two identical protons, each having a nuclear spin polarization of 30%, would have a proton polarization of 60 mM. Thus, different molar polarizations can be obtained for different nuclei within the molecule.

Theoretical background

[032] In conventional hyperpolarization experiments that utilize dynamic nuclear polarization (DNP), the concentration of target nuclei is typically low enough that the magnetic field generated by the target nuclei during polarization buildup is negligible. The same holds true for PHIP, PHIP-

SAH, PHIP-X, and PHIPNOESYS experiments at moderate concentrations. However, numerical studies of PHIP at high concentrations suggest that this is no longer the case when the molar polarization exceeds a certain value. At that point, the magnetic field generated by the target nuclei can become strong enough to exceed the oscillation frequency associated with the splitting of the hydrogen pseudo-spin. This can cause the nonlinear equations, which include the backaction of the nuclei as a mean-field contribution, to become chaotic.

[033] While it may seem possible to eliminate the presence of a demagnetization field in a spherical reaction chamber, this is only achievable with perfectly uniform spatial distributions of the nuclei and their polarization (i.e., of the polarization density). In reality, even in a spherical chamber, these quantities are likely to fluctuate randomly, making it difficult to avoid the demagnetization field entirely. In the chaotic regimes, such random fluctuations may be amplified very rapidly (e.g., exponentially in time), further exacerbating the problem. Furthermore, in parahydrogen-based polarization procedures, the parahydrogenation reaction is subject to random fluctuations, which also make it difficult to avoid the demagnetization field through geometric considerations alone. As such, it is necessary to develop approaches to suppress the effect of the demagnetization field on the polarization dynamics.

[034] The systems and methods described herein solve this problem by combining dipolar decoupling schemes (including, but not limited to, Lee-Goldburg decoupling, MREV-8 decoupling, BLEW- 12 decoupling, or BR-24 decoupling) and concatenated driving fields to develop novel polarization schemes (referred to herein as transverse magnetic field sweep at Lee- Goldburg frame, polarizing MREV-8, polarizing BLEW-12, or polarizing BR-24, respectively) based on parameter sweeps that are highly robust and not limited by the concentration of the molecule undergoing a hyperpolarization procedure.

The regarded system

[035] For our description of hyperpolarization in PHIP and high concentrations, we use a model similar to that introduced in M.C. Korzeczek et al, “Towards a unified picture of polarization transfer - equivalence of DNP and PHIP,” arXiv:2303.07478 (2023) (hereinafter “Korzeczek 2023”) and J. Eills et al, “Singlet order conversion and parahydrogen-induced hyperpolarization of ¹³ C nuclei in near-equivalent spin systems,” J. Magn. Reson. 274, 163-172 (2017), each of which is incorporated herein by reference in its entirety for all purposes. This model was combined with a semi-classical mean-field description of the effects from intermolecular dipole-dipole coupling and the dipolar field (see, e.g., M.H. Levitt, “Demagnetization field effects in two- dimensional solution NMR,” Cone. Magn. Reson. 8, 77-103 (1996), which is incorporated herein by reference in its entirety for all purposes). For the derivation of the transfer sequences, we regard a two-spin system as in Korzeczek 2023.

[036] The full dynamics is described by i) the single-molecule Hamiltonian H _o , ii) the influence of a magnetic field H _B , and iii) the inter-molecular coupling as described by the dipolar field H _dip . (1)

[037] The molecule is described by two (pseudo)-spins S and I, of which the former is driven by a drive (such as a radio-frequency (RF) drive, a transverse magnetic field (B ₁ ) drive, or the like). The spins are coupled by a term of the form We decompose the magnetic field as and assume the non-constant fields to only affect the S spin (due to the frequencies of the non-constant fields). Furthermore, we assume the subsequent contributions to decline in magnitude which ensures the validity of the Rotating-Wave- Approximation (RWA) for linearly polarized RF fields. With , we find that the corresponding Hamiltonian terms are , where H _B0 corresponds to the constant B _o field and sequences can use further driving fields (Bi(t), ...). Here, y _s is the nuclear gyromagnetic ratio of spin S. The contributions for a single molecule in the constant field is given by: (2)

[038] Here,ꞷ _S = y _S B ₀ and = y _H B ₀ are the Larmor frequencies of the S and I spins induced by the magnetic field of magnitude B _o and pointing along the z-axis. As shown in Korzeczek 2023, this Hamiltonian allows for analyzing the properties of different transfer schemes.

[039] For describing the influence of dipole-dipole coupling between molecules in a sample with high concentration, we use a semi-classical mean-field description of the dipolar field. Note, however, that all of the transfer schemes which suppress the contributions of the dipolar field also suppress the contributions from a fully quantum description of dipole-dipole-coupling.

[040] For the mean field description, we first assume that no coherences build up between different molecules, such that the dipolar coupling between the S spins {S _i at positions across the sample leads to coupled Hamiltonians:

[041] Here, . A mean-field assumption now allows us to decouple the Hamiltonians, but requires that magnetization across the sample remains aligned throughout the experiment. In our case, the initial state has = 0 for all molecules, and pulses aim to affect all of the sample equally. In more general cases, the use of e.g. gradient pulses invalidates a mean- field description and leads to highly complex behavior. The mean-field Hamiltonians are:

(4)

[042] Thus, H^ _p is generally dependent on the regarded molecule i and the dependence is parametrized by the matrix D _L which depends on the particle positions. In practice, diffusion in liquid samples leads to a strong averaging of the interaction over positions which suppresses the contributions from nearby molecules. However, the overall form of the terms does not change.

[043] Before we enter the frame corotating with the Larmor precession of S, we explicitly choose the parameterization for the first field with a detuning

[044] We can now enter the “(0)” frame corotating with the (detuned) Larmor precession of S to simplify the description. Using we can discard the oscillating terms and reach:

[045] Here, is a single scalar parameter that can vary for the different molecules in the sample. In this work, we will regard the dynamics for a single, fixed value of (dropping the index z) and explore the range in which a controlled polarization transfer remains successful. As long as all molecules in the sample have values that he inside this range, the combined dynamics remains well-described by the mean-field description. In some cases (e.g., for certain choices of the combined dynamics may be well-described by the mean- field description even for values that fall outside this range. Complicating the given definition of , the true contribution from nearby molecules will be suppressed by motional diffusion as the spherically homogeneous average of is zero. In our case, this removes the strong contributions from adjacent molecules and does not affect the validity of the representative description with the single parameter

Dipolar field influence on non-adapted sequences

[046] For all typical polarization sequences, the rotating-frame operator in the “(1)” frame is predominantly oriented along a two-dimensional plane orthogonal to the direction in which the polarization is accumulated. Here, we assume this to be the z-axis without loss of generality. The reason for this shared property is that contributions along the third (i.e., z) dimension do not contribute to transfer so that maximal transfer rates imply the use of a two- dimensional plane. This property ensures that vanishes and the effective interaction resulting from Average Hamiltonian Theory is equivalent to: ( ₁₀₎ (11)

[047] Here, we removed the contribution from H _dip . As the initial state corresponds to and the transfer A* creates a z-magnetization which is unaffected by the dipolar field term. We use to describe the state with a unitless magnetization Note that we have left out the frame label “(1)” for to emphasize that the symmetry of this term makes it independent of any rotations on only spin S. In this effective interaction we now see that A directly induces a resonance offset to the transition driven by A*. Thus, values cannot be reached by a polarization sequence that is not explicitly adjusted to work in the presence of dipolar fields.

Amplitude sweeps

[048] For an amplitude sweep, assuming that an initial pulse with phase — Y is followed by a continuous wave pulse with amplitude and phase X. We will later choose this to be a linear amplitude sweep. With during the pulse we have: (12) (13) (14)

[049] Inserted into the full Hamiltonian and using similar arguments as before, this gives us: (15)

[050] Here, we have used the fact that the S spin only accrues z-magnetization to get to the second equality. By switching into the frame that corotates with the remaining dipolar field term we find that the corrected Rabi amplitude is enough to formally regain the dipolar field free behavior. With we get: (16)

[051] From this, we see that a reliable transfer via adiabatic amplitude sweep may be possible up to demagnetization fields significantly higher than the demagnetization fields in which unadjusted sequences are effective. Next, we regard how dynamical decoupling can lead to further improvements.

Transfer during Lee-Goldburg decoupling

[052] In this section we introduce a sequence which uses two layers of the driving field where the first is a continuous wave Lee-Goldburg decoupling (LG drive) which suppresses the dipole-dipole interaction on a fast time scale without fully removing the interaction term necessary for polarization transfer. The second driving field is chosen to correspond to a transfer scheme in the effective frame that results from the first drive.

[053] For describing the LG drive, we choose the constant and include the detuning as This leads to: ‘ '

[054] Here, This displays fast oscillations of frequency . The important properties of ^^(t) are: (is) (19)

[055] Note that for Equation (19) to hold, the state must be quasi-static over the integration period, which is fulfilled by the assumption Choosing B ₂ as a suitably amplitude-modulated and phase-shifted, “orthogonal” version of we get: (20) (21)

[056] We now define: [057] Equations (22)-(24) form an orthonormal basis for S with With all of these, we reach the (l’)-frame Hamiltonian:

(25) (26) (27) (28)

[058] This corresponds exactly to the (O)-frame Hamiltonian with 0 and suitably redefined parameters and bases. As an imperfec will not exactly cancel ^we choose the adiabatic amplitude sweep from the previous section as as the sequence for polarization transfer during a time period T. After the sweep, the polarization accumulated on spin S will be oriented along which can be re-oriented along with a rr/2 pulse of phase Finally, the magnetization oriented along can be returned to by adiabatically decreasing to zero. During this period 0 but instead ensures that the state remains unaffected by the dipolar field.

General dipolar decoupling sequences as a basis for polarization transfer [059] Similar to how the continuous-wave Lee-Goldburg decoupling was used in the previous section as a basis for suppressing dipolar coupling without suppressing (allowing the addition of a drive to induce unhindered polarization transfer), similar methods can be applied to arbitrary dipolar decoupling sequences. Such sequences can include frequency-switched Lee- Goldburg, or fully pulsed sequences like MREV-8, BLEW-12, or BR-24, among others. The defining features of this class of dipolar decoupling sequences are: (29) (30)

[060] These properties are sufficient to ensure that, in the Approximate Hamiltonian Theory approximation: (31)

[061] This corresponds to a dipolar field free situation. With we reach: (32)

[062] With this, we reach:

(33)

[063] In principle, it will be necessary to use a that is adapted to the specific dipolar decoupling sequence given by Generally, non-zero terms will arise from frequency contributions in B ₂ as regarded in the (0)-frame which are integer multiples of 1/T ₁ , the repetition rate induced by

[064] Without loss of generality, we now assume that we have access to suitable (0)-frame t° induce the (l’)-frame pulses given by and describe with sin a . This results in the (l’)-frame Hamiltonian: (34) [065] Surrounding an arbitrary polarization sequence that is resonant to m, by an initial pulse and a final pulse on will now lead to polarization transfer with the maximal coupling strength

Dipolar decoupling polarization sequences

[066] With the realization that adding a slow (resonant to a),) precession to the linear term of a dipolar decoupling sequence changes its properties to a polarization sequence without strongly affecting the dipolar decoupling properties, sequences such as MREV-8, BLEW-12, and BR-24 can be modified to serve as polarization sequences. The adjusted sequences can be redefined as follows.

[067] Polarizing MREV-8:

[068] Here, the total duration is T = 12T and the resonance condition is the sequence reverts to the original non-polarizing MREV-8.

[069] Polarizing BLEW- 12 : (36)

[070] Here, the total duration is T = 12T and the resonance condition is the sequence reverts to the original non-polarizing BLEW- 12.

[071] Polarizing BR-24: ( ³⁷⁾

[072] Here, the total duration is T = 24r and the resonance condition is <p = ISrm/. For <p = 0, the sequence reverts to the original non-polarizing BR-24.

[073] The same principles used in constructing the polarizing MREV-8, BLEW-12, and BR-24 sequences can be used to modify arbitrary decoupling sequences with 0 (i.e., sequences which do not decouple chemical shifts).

[074] Similarly, the principles described herein may be used to construct pulse sequences that allow for the generation of pulse sequences that enhance molar polarization in hyperpolarized molecules prepared via alternative hyperpolarization techniques, such as DNP or dissolution DNP.

Methods for generating high molar polarization

[075] FIG. 1 depicts an exemplary method 100 for generating high molar polarization in a hyperpolarized molecule via a PHIP nuclear spin hyperpolarization protocol, in accordance with disclosed embodiments. In some embodiments, the hyperpolarized molecule comprises at least one nucleus. In some embodiments, the at least one nucleus comprises at least one NMR-active nucleus, such as at least one proton, deuterium nucleus, carbon- 13 nucleus, nitrogen- 15 nucleus, oxygen- 17 nucleus, fluorine- 19 nucleus, phosphorous-31 nucleus, or the like.

[076] In some embodiments, the method 100 imparts a molar polarization to the at least one nucleus. In some embodiments, the molar polarization is at least about 50 mM, 60 mM, 70 mM, 80 mM, 90 mM, 100 mM, 110 mM, 120 mM, 130 mM, 140 mM, 150 mM, 160 mM, 170 mM, 180 mM, 190 mM, 200 mM, 210 mM, 220 mM, 230 mM, 240 mM, 250 mM, 260 mM, 270 mM, 280 mM, 290 mM, 300 mM, 310 mM, 320 mM, 330 mM, 340 mM, 350 mM, 360 mM, 370 mM, 380 mM, 390 mM, 400 mM, 410 mM, 420 mM, 430 mM, 440 mM, 450 mM, 460 mM, 470 mM, 480 mM, 490 mM, 500 mM, 510 mM, 520 mM, 530 mM, 540 mM, 550 mM, 560 mM, 570 mM, 580 mM, 590 mM, 600 mM, 610 mM, 620 mM, 630 mM, 640 mM, 650 mM, 660 mM, 670 mM, 680 mM, 690 mM, 700 mM, 710 mM, 720 mM, 730 mM, 740 mM, 750 mM, 760 mM, 770 mM, 780 mM, 790 mM, 800 mM, 810 mM, 820 mM, 830 mM, 840 mM, 850 mM, 860 mM, 870 mM, 880 mM, 890 mM, 900 mM, 910 mM, 920 mM, 930 mM, 940 mM, 950 mM, 960 mM, 970 mM, 980 mM, 990 mM, 1,000 mM, or more. In some embodiments, the molar polarization is at most about 1,000 mM, 990 mM, 980 mM, 970 mM, 960 mM, 950 mM, 940 mM, 930 mM, 920 mM, 910 mM, 900 mM, 890 mM, 880 mM, 870 mM, 860 mM, 850 mM, 840 mM, 830 mM, 820 mM, 810 mM, 800 mM, 790 mM, 780 mM, 770 mM, 760 mM, 750 mM, 740 mM, 730 mM, 720 mM, 710 mM, 700 mM, 690 mM, 680 mM, 670 mM, 660 mM, 650 mM, 640 mM, 630 mM, 620 mM, 610 mM, 600 mM, 590 mM, 580 mM, 570 mM, 560 mM, 550 mM, 540 mM, 530 mM, 520 mM, 510 mM, 500 mM, 490 mM, 480 mM, 470 mM, 460 mM, 450 mM, 440 mM, 430 mM, 420 mM, 410 mM, 400 mM, 390 mM, 380 mM, 370 mM, 360 mM, 350 mM, 340 mM, 330 mM, 320 mM, 310 mM, 300 mM, 290 mM, 280 mM, 270 mM, 260 mM, 250 mM, 240 mM, 230 mM, 220 mM, 210 mM, 200 mM, 190 mM, 180 mM, 170 mM, 160 mM, 150 mM, 140 mM, 130 mM, 120 mM, 110 mM, 100 mM, 90 mM, 80 mM, 70 mM, 60 mM, 50 mM, or less. In some embodiments, the molar polarization is within a range defined by any two of the preceding values.

[077] In the example shown, a solution is obtained at 110. In some embodiments, the solution comprises a derivative of the hyperpolarized molecule. In some embodiments, the derivative comprises at least one unsaturated carbon-carbon double bond or at least one unsaturated carboncarbon triple bond. In some embodiments, the derivative has the form R1 — C = C — R2 or R1 — C = C — R2. Here, R1 and R2 denote sidechains, = denotes a carbon-carbon double bond, and = denotes a carbon-carbon triple bond.

[078] In some embodiments, the unsaturated carbon-carbon double bond or unsaturated carboncarbon triple bond is configured to undergo a hydrogenation reaction with parahydrogen. Thus, at 120, the unsaturated carbon-carbon double bond or the unsaturated carbon-carbon triple bond is hydrogenated with parahydrogen to form a parahydrogenated derivative of the hyperpolarized molecule. In some embodiments, the parahydrogenated derivative has the form R1 — CH* — CH* — R2 or R1 — CH* = CH* — R2. Here, R1 and R2 denote sidechains, — denotes a carboncarbon single bond, = denotes a carbon-carbon double bond, and H* denotes a parahydrogenderived hydrogen atom added across the double bond or triple bond during the hydrogenation reaction.

[079] In some embodiments, the hydrogenation reaction is performed by mixing parahydrogen gas into the solution, such that the parahydrogen gas mixes with the derivative. In some embodiments, the solution contains a hydrogenation catalyst. In some embodiments, the parahydrogen gas is mixed with the derivative in the presence of the hydrogenation catalyst. In some embodiments, the mixture of the parahydrogen gas with the derivative molecule in the presence of the hydrogenation catalyst induces a parahydrogenation reaction between the parahydrogen gas and the derivative.

[080] At 130, a polarization transfer waveform is applied. In some embodiments, the polarization transfer waveform transfers nuclear spin order from at least one of the parahydrogen-derived hydrogen atoms to the at least one nucleus. In some embodiments, the polarization transfer waveform thereby imparts a nuclear spin hyperpolarization to the at least one nucleus. In some embodiments, operation 130 is applied subsequent to operation 120. In some embodiments, the polarization transfer waveform is configured to suppress a dipolar field associated with magnetization that is generated during a buildup of the nuclear spin hyperpolarization. In some embodiments, the polarization transfer waveform comprises any one or more of: a dipolar decoupling sequence, a transverse magnetic field (B _t ) sweep at, for instance, the Lee-Goldburg frame, and a pulse sequence selected from the group consisting of: polarizing MREV-8, polarizing BLEW- 12, and polarizing BR-24.

[081] In some embodiments, operations 110, 120, and 130 generate the hyperpolarized molecule. That is, in some embodiments, operations 110, 120, and 130 form a PHIP nuclear spin polarization protocol.

[082] In some embodiments, the hyperpolarized molecule comprises any molecule of interest described herein. In some embodiments, the hyperpolarized molecule is used in an NMR or MRI experiment.

[083] In other embodiments, nuclear spin polarization from the hyperpolarized molecule is transferred to any molecule of interest described herein and the molecule of interest is used in an NMR or MRI experiment. In some embodiments, the nuclear spin polarization is transferred from the hyperpolarized molecule to the molecule of interest by a PHIPNOESYS procedure or a PHIP- X procedure. That is, in some embodiments, the nuclear spin polarization is transferred from the hyperpolarized molecule to the molecule of interest by an intermolecular NOE between the hyperpolarized molecule and the molecule of interest or by proton exchange between the hyperpolarized molecule and the molecule of interest. [084] In some embodiments, the method 100 further comprises performing at least one purification protocol on the hyperpolarized molecule or the molecule of interest. Examples of purification protocols are described in, for instance, WO2022018514 and WO2022269350, each of which is incorporated herein by reference in its entirety for all purposes.

[085] FIG. 2 depicts an exemplary method 200 for generating high molar polarization in a hyperpolarized molecule via a PHIP-SAH nuclear spin hyperpolarization protocol, in accordance with disclosed embodiments. In some embodiments, the hyperpolarized molecule comprises at least one nucleus. In some embodiments, the at least one nucleus comprises any NMR-active nucleus described herein with respect to FIG. 1.

[086] In some embodiments, the method 200 imparts a molar polarization to the at least one nucleus. In some embodiments, the molar polarization is any molar polarization described herein with respect to FIG. 1.

[087] In the example shown, a solution is obtained at 210. In some embodiments, the solution comprises a derivative of the hyperpolarized molecule. In some embodiments, the derivative comprises at least one unsaturated carbon-carbon double bond or at least one unsaturated carboncarbon triple bond. In some embodiments, the derivative has the form R1 — C = C — R2 or R1 — C = C — R2. Here, R1 and R2 denote sidechains, = denotes a carbon-carbon double bond, and = denotes a carbon-carbon triple bond.

[088] In some embodiments, the unsaturated carbon-carbon double bond or unsaturated carboncarbon triple bond is configured to undergo a hydrogenation reaction with parahydrogen. Thus, at 220, the unsaturated carbon-carbon double bond or the unsaturated carbon-carbon triple bond is hydrogenated with parahydrogen to form a parahydrogenated derivative of the hyperpolarized molecule. In some embodiments, the parahydrogenated derivative has the form R1 — CH* — CH* — R2 or R1 — CH* = CH* — R2. Here, R1 and R2 denote sidechains, — denotes a carboncarbon single bond, = denotes a carbon-carbon double bond, and H* denotes a parahydrogenderived hydrogen atom added across the double bond or triple bond during the hydrogenation reaction.

[089] In some embodiments, the hydrogenation reaction is performed by mixing parahydrogen gas into the solution, such that the parahydrogen gas mixes with the derivative. In some embodiments, the solution contains a hydrogenation catalyst. In some embodiments, the parahydrogen gas is mixed with the derivative in the presence of the hydrogenation catalyst. In some embodiments, the mixture of the parahydrogen gas with the derivative in the presence of the hydrogenation catalyst induces a parahydrogenation reaction between the parahydrogen gas and the derivative.

[090] At 230, a polarization transfer waveform is applied. In some embodiments, the polarization transfer waveform transfers nuclear spin order from at least one of the parahydrogen-derived hydrogen atoms to the at least one nucleus. In some embodiments, the polarization transfer waveform thereby imparts a nuclear spin hyperpolarization to the at least one nucleus. In some embodiments, operation 230 is applied subsequent to operation 220. In some embodiments, the polarization transfer waveform is configured to suppress a dipolar field associated with magnetization that is generated during a buildup of the nuclear spin hyperpolarization. In some embodiments, the polarization transfer waveform comprises polarization transfer waveform described herein with respect to FIG. 1.

[091] At 240, the parahydrogenated derivative is hydrolyzed. In some embodiments, hydrolyzing the parahydrogenated derivative forms the hyperpolarized molecule. In some embodiments, the parahydrogenated derivative is mixed with a hydrolysis agent, such as sodium hydroxide (NaOH) or potassium hydroxide (KOH). In some embodiments, the hydrolysis agent hydrolyzes the parahydrogenated derivative of the molecule of interest, forming a hydrolyzed sidearm and the hyperpolarized molecule via a PHIP-SAH interaction. Examples of PHIP-SAH interactions can be found in, for instance, WO2022157534, WO2022018514, and WO2021198776, each of which is incorporated herein by reference in its entirety for all purposes.

[092] In some embodiments, operations 210, 220, 230, and 240 generate the hyperpolarized molecule. That is, in some embodiments, operations 210, 220, 230, and 240 form a PHIP-SAH nuclear spin polarization protocol.

[093] In some embodiments, the hyperpolarized molecule comprises any molecule of interest described herein. In some embodiments, the hyperpolarized molecule is used in an NMR or MRI experiment.

[094] In other embodiments, nuclear spin polarization from the hyperpolarized molecule is transferred to any molecule of interest described herein and the molecule of interest is used in an NMR or MRI experiment. In some embodiments, the nuclear spin polarization is transferred from the hyperpolarized molecule to the molecule of interest by a PHIPNOESYS procedure or a PHIP- X procedure. That is, in some embodiments, the nuclear spin polarization is transferred from the hyperpolarized molecule to the molecule of interest by an intermolecular NOE between the hyperpolarized molecule and the molecule of interest or by proton exchange between the hyperpolarized molecule and the molecule of interest.

[095] In some embodiments, the method 200 further comprises performing at least one purification protocol on the hyperpolarized molecule or the molecule of interest. In some embodiments, the at least one purification protocol comprise any purification protocol described herein with respect to FIG. 1. Molecules of interest and biorelevant imaging agents

[096] The disclosed embodiments include systems and methods for producing and utilizing molecules of interest with clinically relevant polarizations, concentrations, volumes, or purities. In some embodiments, the method is for preparing an NMR material (also referred to herein as a “molecule of interest”). In some embodiments, the NMR material is suitable for use in NMR or MRI operations. In some embodiments, the NMR material increases NMR or MRI signal and signal-to-noise ratio (SNR). In some embodiments, the NMR material is suitable for use in solution NMR spectroscopy. In some embodiments, the NMR material is a chemical compound. In some embodiments, the NMR material is a metabolite (e.g., a molecule with a biological relevance such as an amino acid, a saccharide, a derivative thereof, or the like), such as a metabolite suitable for use in an NMR metabolomics application. In some embodiments, the NMR material is suitable for in-vitro probing of the metabolism of a cell culture or other biological tissue. In some embodiments, the NMR material is used in an NMR probe to investigate a transient effect in which high signal enhancement due to hyperpolarization is needed, such as proton exchange between water and biomolecules. In some embodiments, the NMR material is a small molecule or metabolite suitable for injection into a cell, tissue or organism for detection in an MRI scan. In some embodiments, the NMR material is introduced into a chamber for further analysis by NMR or MRI operations. In some embodiments, the NMR material is enriched with one or more deuterium ( ² H) or carbon- 13 ( ¹³ C) atoms.

[097] Consistent with disclosed embodiments, the NMR material can include biorelevant imaging agents. In some embodiments, the biorelevant imaging agent can be suitable for use in NMR or MRI operations. In some embodiments, the biorelevant imaging agent may increase NMR or MRI signal or signal-to-noise ratio (SNR). In some embodiments, the biorelevant imaging agent can be suitable for use in solution NMR spectroscopy. In some embodiments, the biorelevant imaging agent may be a metabolite (e.g., a molecule with a biological relevance such as an amino acid, a saccharide, a derivative thereof, or the like), such as a metabolite suitable for use in an NMR metabolomics application. In some embodiments the biorelevant imaging agent is used for perfusion imaging or contrast enhanced imaging in MRI scans. In some embodiments, the biorelevant imaging agent is suitable for in-vitro probing of the metabolism of a cell culture or other biological tissue. In some embodiments, the biorelevant imaging agent is used for in-vitro probing of the metabolism of a cell culture or other biological tissue. In some embodiments, the biorelevant imaging agent is used in an NMR probe to investigate a transient effect in which high signal enhancement due to hyperpolarization is needed, such as proton exchange between water and biomolecules. In some embodiments, the biorelevant imaging agent is a small molecule or metabolite suitable for injection into a cell, tissue or organism for detection in an MRI scan. In some embodiments, the biorelevant imaging agent is introduced into a chamber for further analysis by NMR or MRI operations. In some embodiments, the biorelevant imaging agent is enriched with one or more ² H or ¹³ C atoms.

[098] In some embodiments, the biorelevant imaging agent comprises pyruvate, lactate, alphaketoglutarate, bicarbonate, fumarate, urea, dehydroascorbate, glutamate, glutamine, acetate, dihydroxyacetone, acetoacetate, glucose, ascorbate, zymonate, alanine, fructose, imidazole, nicotinamide, nitroimidazole, pyrazinamide, isoniazid, a conjugate acid of any of the foregoing, natural and unnatural amino acids, esters thereof, or ² H, ¹³ C, or nitrogen-15 ( ¹⁵ N) enriched versions of any of the foregoing. In some embodiments, the biorelevant imaging agent comprises pyruvate, lactate, alpha-ketoglutarate. In some embodiments, the biorelevant imaging agent comprises pyruvate. In some embodiments, the biorelevant imaging agent comprises lactate. In some embodiments, the biorelevant imaging agent comprises alpha-ketoglutarate (e.g., ethyl alphaketoglutarate).

[099] In some embodiments, the biorelevant imaging agent comprises at least one non-hydrogen nuclear spin. In some embodiments, the non- hydrogen nuclear comprises at least one spin- 1/2 atom. In some embodiments, the non-hydrogen nuclear spin comprises ¹³ C or ¹⁵ N. In some embodiments, the biorelevant imaging agent is at least partially isotopically labeled with the nonhydrogen nuclear spin. In some embodiments, the biorelevant imaging agent is at least partially enriched with the non-hydrogen nuclear spin when compared to an analog of the biorelevant imaging agent that features the non-hydrogen nuclear spin at its natural abundance. In some embodiments, the biorelevant imaging agent is enriched to feature the non-hydrogen nuclear spin at an abundance of at least about 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 91%, 92%, 93%, 94%,

95%, 96%, 97%, 98%, 99%, or more, at most about 99%, 98%, 97%, 96%, 95%, 94%, 93%, 92%,

91%, 90%, 85%, 80%, 75%, 70%, 65%, 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, 20%, 15%,

10%, 9%, 8%, 7%, 6%, 5%, 4%, 3%, 2%, 1%, or less, or an abundance that is within a range defined by any two of the preceding values.

[0100] In some embodiments, the non-hydrogen nuclear spin replaces an NMR-inactive (i.e., spin- 0) nucleus (e.g., ¹² C or a quadrupolar (i.e., spin > 1/2) nucleus (e.g., nitrogen-14, ¹⁴ N) of the analog of the biorelevant imaging agent that features the non-hydrogen nuclear spin at its natural abundance. For example, an analog of pyruvate that features ¹³ C at its natural abundance may include about 98.9% ¹² C and about 1.1% ¹³ C at either C* in the structure H3C-C*(=O)-C*OOH. As a biorelevant imaging agent, pyruvate may instead be isotopically enriched with ¹³ C such that one or both C* comprises ¹³ C at any abundance described herein. As used herein, *C and C* describe a carbon that can be either a ¹² C or ¹³ C carbon isotope. As another example, an analog of urea that features ¹⁵ N at its natural abundance may include about 99.6% ¹⁴ N and about 0.4% ¹⁵ N at either N* in the structure H2N*-C(=O)-*NH2. As a biorelevant imaging agent, urea may instead be isotopically enriched with ¹⁵ N such that one or both N* comprises ¹⁵ N at any abundance described herein. As used herein, *N and N* describe a nitrogen that can be either a ¹⁴ N or ¹⁵ N nitrogen isotope.

Precipitation

[0101] In various embodiments, the hyperpolarized molecule or the molecule of interest can be crystalized or precipitated out of the solutions described herein. The disclosed embodiments are not limited to any particular method of inducing such precipitation. For example, such precipitation can be induced by through a change in temperature or pH, application of an electromagnetic stimulus (e.g., optical radiation, such as ultraviolet radiation or optical radiation at another suitable wavelength or wavelengths), mechanical stimulus (e.g., ultrasound, agitation, or another suitable mechanical stimulus), addition of another solute or solvent to the solution, or another suitable method, or any combination thereof. In some embodiments, following precipitation, the molecule of interest can be separated from the solution (e.g., using a filter, or another suitable method). In some embodiments, the molecule of interest may then be combined or redissolved into another solution. This solution may have desirable characteristics (e.g., biocompatibility, concentration, volume, temperature, pH, polarity, or other relevant characteristics, or any combination thereof) for the intended NMR or MRI application.

Use of molecules of interest and biorelevant imaging agents

[0102] In some embodiments, at least a portion of the molecule of interest can be injected into a subject or patient for use in an MRI experiment. In various embodiments, at least a portion of the molecule of interest can be used in NMR spectroscopy. At least one NMR or MRI pulse sequence can be applied to the molecule of interest.

[0103] The foregoing description has been presented for purposes of illustration. It is not exhaustive and is not limited to precise forms or embodiments disclosed. Modifications and adaptations of the embodiments will be apparent from consideration of the specification and practice of the disclosed embodiments. For example, the described implementations include hardware, but systems and methods consistent with the present disclosure can be implemented with hardware and software. In addition, while certain components have been described as being coupled to one another, such components may be integrated with one another or distributed in any suitable fashion.

[0104] Moreover, while illustrative embodiments have been described herein, the scope includes any and all embodiments having equivalent elements, modifications, omissions, combinations (e.g., of aspects across various embodiments), adaptations or alterations based on the present disclosure. The elements in the claims are to be interpreted broadly based on the language employed in the claims and not limited to examples described in the present specification or during the prosecution of the application, which examples are to be construed as nonexclusive. Further, the steps of the disclosed methods can be modified in any manner, including reordering steps or inserting or deleting steps.

[0105] The features and advantages of the disclosure are apparent from the detailed specification, and thus, it is intended that the appended claims cover all systems and methods falling within the true spirit and scope of the disclosure. As used herein, the indefinite articles “a” and “an” mean “one or more.” Similarly, the use of a plural term does not necessarily denote a plurality unless it is unambiguous in the given context. Further, since numerous modifications and variations will readily occur from studying the present disclosure, it is not desired to limit the disclosure to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the disclosure.

[0106] As used herein, unless specifically stated otherwise, the term “or” encompasses all possible combinations, both conjunctive and disjunctive, except where infeasible. For example, if it is stated that a component may include A or B, then, unless specifically stated otherwise or infeasible, the component may include A alone, or B alone, or A and B. As a second example, if it is stated that a component may include A, B, or C, then, unless specifically stated otherwise or infeasible, the component may include A alone, or B alone, or C alone, or A and B, or A and C, or B and C, or A and B and C.

EXAMPLES

Example 1: Numerical simulations of polarization transfer dynamics

[0107] The systems and methods herein were used to numerically evaluate polarization transfer dynamics for a variety of molecules using a variety of unadjusted and adjusted pulse sequences. The Hamiltonian used corresponded to a two-spin system for describing homonuclear PHIP with the following correspondences. The hydrogen-pair with J-coupling of strength u>i = J was driven by the pulses, and the differential coupling A _± to the heteronuclear ¹³ C spin provided a term which allows for transitions between the singlet and triplet states of the hydrogen nuclei. In the numerical simulations, the homonuclear case was regarded, where the drives affected the hydrogens and the heteronuclear spin only served as a background to induce the necessary chemical shift. A suitable drive canceled the Hamiltonian terms for both individual spins and thus also decoupled the combined state. [0108] For the numerical simulations, parameters from three different molecules (carbon- 13 labeled deuterated dimethyl maleate, carbon- 13 labeled fumaric acid, and deuterated ethyl acetate) were used. For fumaric acid, a molecule without a carbon- 13 spin label was used. Thus, in order to induce a chemical shift, fumaric acid was simulated using a magnetic field amplitude of 100 millitesla (mT) instead of the 100 microtesla (pT) used for the other two molecules. The numerical simulations model all 3 (2 for ethyl acetate) spins explicitly instead of the representative Hamiltonian in the previous sections. With the J-coupling between the hydrogens J, and (where applicable) the heteronuclear J-coupling between the two hydrogens and the carbon spin and /®, the relevant parameters for the different molecules become (1- ¹³ C,de)-dimethyl maleate: J = -fumanc acid: chemical shift = 2.88 parts-per-million (ppm) «

Example 2; Numerical simulations of polarizing MREV-8, polarizing BLEW- 12, polarizing BR-24, and transverse magnetic field sweep at Lee-Goldburg frame for (1- ¹³ C,d6)-dimethyl maleate

[0109] FIG. 3 shows exemplary numerical simulations of molar polarization versus concentration for the polarizing MREV-8 (“MREV-8 adj” in FIG. 3), polarizing BLEW-12 (“BLEW-12 adj” in FIG. 3), polarizing BR-24 (“BR-24 adj” in FIG. 3), and transverse magnetic field sweep at Lee- Goldburg frame (“LG+sweep” in FIG. 3) pulse sequences for (1- ¹³ C,d ₆ )-dimethyl maleate. The numerical simulations were conducted as described herein with respect to Example 1. Simulations were also conducted for SLIC and a pure transverse magnetic field sweep (“sweep” in FIG. 3) to enable proper comparison between the pulse sequences described herein and prior pulse sequences. The concentration is expressed in units of HZ for convenience in executing the simulations. As discussed herein, the concentration can be converted into units of mM by multiplying by a proportionality constant. Similarly ,the molar polarization is expressed in units of (fractional) polarization times (2TT) HZ and can be converted to the molar polarization in units of mM by multiplying by a proportionality constant. As shown in FIG. 3, the pulse sequences described herein clearly outperform the SLIC and pure transverse magnetic field sweep approaches, with the transverse magnetic field sweep at Lee-Goldburg frame achieving the highest molar polarizations. Example 3: Numerical simulations of polarizing MREV-8, polarizing BLEW- 12, polarizing BR-24, and transverse magnetic field sweep at Lee-Goldburg frame for (l- ¹³ C)-fumaric acid [0110] FIG. 4 shows exemplary numerical simulations of molar polarization versus concentration for the polarizing MREV-8 (“MREV-8 adj” in FIG. 4), polarizing BLEW-12 (“BLEW-12 adj” in FIG. 4), polarizing BR-24 (“BR-24 adj” in FIG. 4), and transverse magnetic field sweep at Lee- Goldburg frame (“LG+sweep” in FIG. 4) pulse sequences for (l- ¹³ C)-fumaric acid. The numerical simulations were conducted as described herein with respect to Example 1. Simulations were also conducted for SLIC and a pure transverse magnetic field sweep (“sweep” in FIG. 4) to enable proper comparison between the pulse sequences described herein and prior pulse sequences. The concentration is expressed in units of (2TT) HZ for convenience in executing the simulations. As discussed herein, the concentration can be converted into units of mM by multiplying by a proportionality constant. Similarly ,the molar polarization is expressed in units of (fractional) polarization times (2TT) HZ and can be converted to the molar polarization in units of mM by multiplying by a proportionality constant. As shown in FIG. 4, the pulse sequences described herein clearly outperform the SLIC and pure transverse magnetic field sweep approaches, with the transverse magnetic field sweep at Lee-Goldburg frame achieving the highest molar polarizations.

Example 4: Numerical simulations of polarizing MREV-8, polarizing BLEW- 12, polarizing BR-24, and transverse magnetic field sweep at Lee-Goldburg frame for ( 1.2-.d2)-ethyl acetate [0111] FIG. 5 shows exemplary numerical simulations of molar polarization versus concentration for the polarizing MREV-8 (“MREV-8 adj” in FIG. 5), polarizing BLEW-12 (“BLEW-12 adj” in FIG. 5), polarizing BR-24 (“BR-24 adj” in FIG. 5), and transverse magnetic field sweep at Lee- Goldburg frame (“LG+sweep” in FIG. 5) pulse sequences for (l,2-d2)-ethyl acetate. The numerical simulations were conducted as described herein with respect to Example 1. Simulations were also conducted for SLIC and a pure transverse magnetic field sweep (“sweep” in FIG. 5) to enable proper comparison between the pulse sequences described herein and prior pulse sequences. The concentration is expressed in units of (2TT) HZ for convenience in executing the simulations. As discussed herein, the concentration can be converted into units of mM by multiplying by a proportionality constant. Similarly ,the molar polarization is expressed in units of (fractional) polarization times (2TT) HZ and can be converted to the molar polarization in units of mM by multiplying by a proportionality constant. As shown in FIG. 5, the pulse sequences described herein clearly outperform the SLIC and pure transverse magnetic field sweep approaches, with the transverse magnetic field sweep at Lee-Goldburg frame achieving the highest molar polarizations. Example 5: Experimental demonstration of high molar polarization for (1- ¹³ C, del-dim ethyl maleate using transverse magnetic field sweep at Lee-Goldburg frame

[0112] The systems and methods described herein were utilized to impart a high molar polarization of up to 450 mM in (l- ¹³ C,de)-dimethyl maleate. The precursor solution for (l- ¹³ C,d6)-dimethyl maleate was prepared by dissolving 5 mM [Rh(dppb)(COD)]BF4 catalyst (CAS number: 79255- 71-3) into acetone-de. Varied amounts of (l- ¹³ C,de)-dimethyl acetylenedicarboxylate was mixed in for different experiment: 20, 40, 80, 160, 320, 640, and 1080 mM for each concentration point in the data series provided herein. Para-hydrogen was produced by ARS para-hydrogen generator packed with an iron monohydrate catalyst, running at 22 K temperature and producing gas with para- enrichment level of ~93%.

[0113] Each experiment started by injecting 500 microliters (pL) of solution into a tube and bubbling para-enriched hydrogen gas through the solution at 10 bar pressure at bias field of 96 pT. This was followed by nitrogen bubbling at 10 bar to stop the reaction proceeding further. To avoid fast singlet order decay, ^J H decoupling was provided throughout the entire bubbling period which in all experiments was fixed to 30 seconds (s).

[0114] Polarization transfer was performed in two different ways. The first method consisted of transverse field swept up from 0 Hz to 25 Hz in amplitude (with respect to ¹ H) and followed by adiabatic pulse. The pulse was arranged by ramping the transverse field amplitude down in 1 second with a gradual carrier frequency shift of -200 Hz.

[0115] The second method included an off-resonant driving during the polarization transfer such that effective field B _e was at the angle 9 _e with respect to the bias field. The effective field amplitude was set to 600 Hz and 400 Hz for the experiments described with respect to FIGs. 6 and 7, respectively. After the transfer flip-back pulse was performed by ramping the transverse field amplitude down in 1 second with a gradual carrier frequency shift of -200 Hz. Polarization transfer was done by ramping modulation of the off-resonant driving field amplitude from 0 Hz to 25 Hz (with respect to ¹ H). Modulation frequency was set to match the effective field amplitude. To perform adiabatic pulse along the effective field, the modulation amplitude was ramped down in 1 second with a gradual modulation frequency shift of -200 Hz.

[0116] The ¹ H free-induction decays were initiated by a small flip angle hard pulse of 20 kHz radio-frequency (RF) amplitude and recorded with 131 point density at a spectral width of 400 ppm. Additional 1H decoupling was used for all experiments. Thermal equilibrium 'H spectra were recorded at room temperature with a recycle delay of 90 s and with 90 degrees flip angle pulse. When estimating polarization level, the flip angle scaling factor was taken into account.

[0117] FIG. 6 shows exemplary ^J H molar polarizations of hyperpolarized (l- ¹³ C,d6)-dimethyl maleate as a function of concentration. Data points were acquired with the transverse magnetic field sweep at Lee-Goldburg frame (black dots) and amplitude-swept SLIC (grey dots) pulse sequences. The amplitude-swept SLIC duration was set to 2 seconds and the Lee-Goldburg effective field amplitude was set to 600 Hz. The dashed line represents linear dependency for a fixed polarization level of 47%. Note that the molar polarization is calculated as the polarization times the concentration times a factor of two in order to account for the presence of two polarized protons in dimethyl maleate following PHIP polarization. The re-scaled inset is provided for clarity. As shown in FIG. 6, the transverse magnetic field sweep at Lee-Goldburg frame pulse sequence achieved molar polarization levels of up to 450 mM, compared with molar polarization levels of approximately 50 mM using a standard amplitude-swept SLIC pulse sequence.

[0118] FIG. 7 shows exemplary 'H spin polarizations of hyperpolarized (l- ¹³ C,de)-dimethyl maleate as a function of effective angle of Lee-Goldburg decoupling. Data points acquired at concentrations of 17 mM and 223 mM are shown in grey and black, respectively. The amplitude- swept SLIC duration was set to 4 seconds and the Lee-Goldburg effective field amplitude was set to 400 Hz. The dashed lines indicate the level of polarization acquired with the transverse magnetic field sweep at Lee-Goldburg frame pulse sequence derived in this work at high and low concentration. The magic angle of approximately 54.7° is indicated separately. As shown in FIG. 7, polarization was maximized at the magic angle.

Example 6: Experimental demonstration of high molar polarization for (1- ¹³ C, del-dim ethyl maleate using polarizing MREV-8 [0119] FIG. 8 shows an exemplary hyperpolarized ^J H spectrum of l- ¹³ C-de-dimethyl maleate acquired at 9.41 T magnetic field after polarization transfer using the polarizing MREV-8 sequence. The thermally polarized spectrum below was acquired at room temperature after the hyperpolarization experiment. The MREV-8 sequence was performed in a 200 pT bias field with pulse amplitude set to 400 Hz with respect to ¹ H nutation, free evolution time set to 0.625 ms, and using 30 loops, amounting to a total duration of 0.3 s. Hydrogenation was done by bubbling parahydrogen at 10 bar for 25 seconds and bubbling nitrogen at 10 bar for 5 seconds under 'H continuous wave decoupling with an amplitude of 3 pT. As shown in FIG. 8, a polarization of approximately 20% was achieved for a l- ¹³ C-d6-dimethyl maleate concentration of approximately 1 molar (M) = 1,000 mM. Since dimethyl maleate contains two polarized protons following PHIP polarization, this corresponds to a molar polarization of approximately 400 mM.

RECITATION OF EMBODIMENTS

[0120] Embodiment 1. A method comprising:

(a) obtaining a solution comprising a hyperpolarized molecule dissolved therein, the hyperpolarized molecule comprising at least one nucleus having a molar polarization of at least 50 millimolar (mM).

[0121] Embodiment 2. The method of Embodiment 1 , further comprising, prior to (a), performing a nuclear spin hyperpolarization protocol on the hyperpolarized molecule to thereby impart the molar polarization to the at least one nucleus.

[0122] Embodiment 3. The method of Embodiment 2, wherein the nuclear spin hyperpolarization protocol comprises:

(b) obtaining a solution comprising a derivative of the hyperpolarized molecule, the derivative comprising at least one unsaturated carbon-carbon double bond or unsaturated carbon-carbon triple bond and having the form R1 — C = C — R2 or R1 — C = C — R2, wherein R1 and R2 comprise sidechains;

(c) hydrogenating the double bond or triple bond with parahydrogen to form a parahydrogenated derivative of the hyperpolarized molecule, the parahydrogenated derivative having the form R 1 — CH* — CH* — R2 or R1 — CH* = CH* — R2, wherein H* denotes a parahydrogen-derived hydrogen atom added across the double bond or triple bond; and

(d) applying a polarization transfer waveform to transfer nuclear spin order from at least one of the parahydrogen-derived hydrogen atoms to the at least one nucleus, thereby imparting a nuclear spin hyperpolarization to the at least one nucleus.

[0123] Embodiment 4. The method of Embodiment 3, wherein the polarization transfer waveform is configured to suppress a dipolar field associated with magnetization that is generated during a buildup of the nuclear spin hyperpolarization.

[0124] Embodiment 5. The method of Embodiment 3 or 4, wherein the polarization transfer waveform comprises a dipolar decoupling sequence.

[0125] Embodiment 6. The method of Embodiment 4 or 5, wherein the polarization transfer waveform further comprises a concatenated driving field based on a parameter sweep.

[0126] Embodiment 7. The Embodiment of claim 6, wherein the parameter sweep comprises a transverse magnetic field (B _t ) sweep.

[0127] Embodiment 8. The method of any one of Embodiments 3-7, wherein the polarization transfer waveform comprises a B sweep at Lee-Goldburg frame.

[0128] Embodiment 9. The method of any one of Embodiments 3-7, wherein the polarization transfer waveform comprises a pulse sequence selected from the group consisting of: polarizing MREV-8, polarizing BLEW-12, and polarizing BR-24.

[0129] Embodiment 10. The method of any one of Embodiments 3-9, wherein (b)-(d) generate the hyperpolarized molecule.

[0130] Embodiment 11. The method of any one of Embodiments 3-9, further comprising: (e) hydrolyzing the parahydrogenated derivative to thereby form the hyperpolarized molecule.

[0131] Embodiment 12. The method of Embodiment 10 or 11, further comprising using the hyperpolarized molecule in a nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) experiment, wherein the hyperpolarized molecule comprises a molecule of interest.

[0132] Embodiment 13. The method of Embodiment 10 or 11, further comprising: (f) transferring nuclear spin polarization from the hyperpolarized molecule to a molecule of interest and (g) using the molecule of interest in an NMR or MRI experiment.

[0133] Embodiment 14. The method of Embodiment 13, wherein (f) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by a parahydrogen-induced polarization nuclear Overhauser effect system (PHIPNOESYS) procedure. [0134] Embodiment 15. The method of Embodiment 13, wherein (f) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by a parahydrogen-induced polarization relayed via proton exchange (PHIP-X) procedure.

[0135] Embodiment 16. The method of Embodiment 12 or 13, wherein the molecule of interest comprises a biorelevant imaging agent.

[0136] Embodiment 17. The method of Embodiment 16, wherein the biorelevant imaging agent is selected from the group consisting of: pyruvate, glutamate, glutamine, lactate, acetate, acetoacetate, zymonate, alanine, fructose, fumarate, bicarbonate, urea, dehydroascorbate, alpha- ketoglutarate, dihydroxyacetone, glucose, ascorbate, and conjugate acids thereof.

[0137] Embodiment 18. The method of any one of Embodiments 1-17, wherein the molar polarization comprises a product of a concentration of the at least one nucleus and a nuclear spin polarization of the at least one nucleus.

[0138] Embodiment 19. The method of any one of Embodiments 1-18, wherein the molar polarization is at least 60 mM, 70 mM, 80 mM, 90 mM, 100 mM, 110 mM, 120 mM, 130 mM, 140 mM, 150 mM, 160 mM, 170 mM, 180 mM, 190 mM, 200 mM, 210 mM, 220 mM, 230 mM,

240 mM, 250 mM, 260 mM, 270 mM, 280 mM, 290 mM, 300 mM, 310 mM, 320 mM, 330 mM,

340 mM, 350 mM, 360 mM, 370 mM, 380 mM, 390 mM, 400 mM, 410 mM, 420 mM, 430 mM,

440 mM, 450 mM, 460 mM, 470 mM, 480 mM, 490 mM, 500 mM, 510 mM, 520 mM, 530 mM,

540 mM, 550 mM, 560 mM, 570 mM, 580 mM, 590 mM, 600 mM, 610 mM, 620 mM, 630 mM,

640 mM, 650 mM, 660 mM, 670 mM, 680 mM, 690 mM, 700 mM, 710 mM, 720 mM, 730 mM,

740 mM, 750 mM, 760 mM, 770 mM, 780 mM, 790 mM, 800 mM, 810 mM, 820 mM, 830 mM,

840 mM, 850 mM, 860 mM, 870 mM, 880 mM, 890 mM, 900 mM, 910 mM, 920 mM, 930 mM,

940 mM, 950 mM, 960 mM, 970 mM, 980 mM, 990 mM, or 1,000 mM.

[0139] Embodiment 20. The method of any one of Embodiments 1-19, wherein the at least one nucleus comprises at least one proton ( ¹ H), carbon-13 ( ¹³ C), nitrogen-15 ( ¹⁵ N), fluorine-19 ( ¹⁹ F), or phosphate-31 ( ³¹ P) nucleus.

[0140] Embodiment 21. A composition comprising: a solution comprising a hyperpolarized molecule dissolved therein, the hyperpolarized molecule comprising at least one nucleus having a molar polarization of at least 50 millimolar (mM).

[0141] Embodiment 22. The composition of Embodiment 21, wherein the hyperpolarized molecule is generated by performing a nuclear spin hyperpolarization protocol on the hyperpolarized molecule to thereby impart the molar polarization to the at least one nucleus.

[0142] Embodiment 23. The composition of Embodiment 22, wherein the nuclear spin hyperpolarization protocol comprises:

(a) obtaining a solution comprising a derivative of the hyperpolarized molecule, the derivative comprising at least one unsaturated carbon-carbon double bond or unsaturated carbon-carbon triple bond and having the form R1 — C = C — R2 or R1 — C = C — R2, wherein R1 and R2 comprise sidechains;

(b) hydrogenating the double bond or triple bond with parahydrogen to form a parahydrogenated derivative of the hyperpolarized molecule, the parahydrogenated derivative having the form R 1 — CH* — CH* — R2 or R1 — CH* = CH* — R2, wherein H* denotes a parahydrogen-derived hydrogen atom added across the double bond or triple bond; and

(c) applying a polarization transfer waveform to transfer nuclear spin order from at least one of the parahydrogen-derived hydrogen atoms to the at least one nucleus, thereby imparting a nuclear spin hyperpolarization to the at least one nucleus.

[0143] Embodiment 24. The composition of Embodiment 23, wherein the polarization transfer waveform is configured to suppress a dipolar field associated with magnetization that is generated during a buildup of the nuclear spin hyperpolarization.

[0144] Embodiment 25. The composition of Embodiment 23 or 24, wherein the polarization transfer waveform comprises a dipolar decoupling sequence.

[0145] Embodiment 26. The composition of Embodiment 24 or 25, wherein the polarization transfer waveform further comprises a concatenated driving field based on a parameter sweep. [0146] Embodiment 27. The composition of Embodiment 26, wherein the parameter sweep comprises a transverse magnetic field (B _t ) sweep.

[0147] Embodiment 28. The composition of any one of Embodiments 23-27, wherein the polarization transfer waveform comprises a B sweep at Lee-Goldburg frame.

[0148] Embodiment 29. The composition of any one of Embodiments 23-27, wherein the polarization transfer waveform comprises a pulse sequence selected from the group consisting of: polarizing MREV-8, polarizing BLEW-12, and polarizing BR-24.

[0149] Embodiment 30. The composition of any one of Embodiments 23-29, wherein (a)-(c) generate the hyperpolarized molecule.

[0150] Embodiment 31. The composition of any one of Embodiments 23-29, wherein the hyperpolarized molecule is further generated by: (d) hydrolyzing the parahydrogenated derivative to thereby form the hyperpolarized molecule.

[0151] Embodiment 32. The composition of Embodiment 30 or 31, wherein the hyperpolarized molecule is for use in a nuclear magnetic resonance (NMR) or magnetic resonance imaging (MRI) experiment, wherein the hyperpolarized molecule comprises a molecule of interest.

[0152] Embodiment 33. The composition of Embodiment 31 or 32, wherein the hyperpolarized molecule is for use for: (e) transferring nuclear spin polarization from the hyperpolarized molecule to a molecule of interest and (f) using the molecule of interest in an NMR or MRI experiment.

[0153] Embodiment 34. The composition of Embodiment 33, wherein (e) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by a parahydrogen-induced polarization nuclear Overhauser effect system (PHIPNOESYS) procedure. [0154] Embodiment 35. The composition of Embodiment 33, wherein (e) comprises transferring the nuclear spin polarization from the hyperpolarized molecule to the molecule of interest by a parahydrogen-induced polarization relayed via proton exchange (PHIP-X) procedure.

[0155] Embodiment 36. The composition of Embodiment 34 or 35, wherein the molecule of interest comprises a biorelevant imaging agent.

[0156] Embodiment 37. The composition of Embodiment 36, wherein the biorelevant imaging agent is selected from the group consisting of: pyruvate, glutamate, glutamine, lactate, acetate, acetoacetate, zymonate, alanine, fructose, fumarate, bicarbonate, urea, dehydroascorbate, alphaketoglutarate, dihydroxyacetone, glucose, ascorbate, and conjugate acids thereof.

[0157] Embodiment 38. The composition of any one of Embodiments 21-37, wherein the molar polarization comprises a product of a concentration of the at least one nucleus and a nuclear spin polarization of the at least one nucleus.

[0158] Embodiment 39. The composition of any one of Embodiments 21-38, wherein the molar polarization is at least 60 mM, 70 mM, 80 mM, 90 mM, 100 mM, 110 mM, 120 mM, 130 mM, 140 mM, 150 mM, 160 mM, 170 mM, 180 mM, 190 mM, 200 mM, 210 mM, 220 mM, 230 mM, 240 mM, 250 mM, 260 mM, 270 mM, 280 mM, 290 mM, 300 mM, 310 mM, 320 mM, 330 mM, 340 mM, 350 mM, 360 mM, 370 mM, 380 mM, 390 mM, 400 mM, 410 mM, 420 mM, 430 mM, 440 mM, 450 mM, 460 mM, 470 mM, 480 mM, 490 mM, 500 mM, 510 mM, 520 mM, 530 mM, 540 mM, 550 mM, 560 mM, 570 mM, 580 mM, 590 mM, 600 mM, 610 mM, 620 mM, 630 mM, 640 mM, 650 mM, 660 mM, 670 mM, 680 mM, 690 mM, 700 mM, 710 mM, 720 mM, 730 mM, 740 mM, 750 mM, 760 mM, 770 mM, 780 mM, 790 mM, 800 mM, 810 mM, 820 mM, 830 mM, 840 mM, 850 mM, 860 mM, 870 mM, 880 mM, 890 mM, 900 mM, 910 mM, 920 mM, 930 mM, 940 mM, 950 mM, 960 mM, 970 mM, 980 mM, 990 mM, or 1,000 mM. [0159] Embodiment 40. The composition of any one of Embodiments 21-39, wherein the at least one nucleus comprises at least one proton ( ¹ H), carbon-13 ( ¹³ C), nitrogen-15 ( ¹⁵ N), fluorine-19 ( ¹⁹ F), or phosphate-31 ( P) nucleus.