A new category of crystalline polymer electrolyte prepared by the supramolecular self‐assembly of polyethylene oxide (PEO), α‐cyclodextrin (α‐CD), and LiAsF6 is reported. The polymer electrolyte ...consists of the nanochannels formed by α‐CDs in which the PEO/Li+ complexes are confined. The nanochannels formed by α‐CD provide the pathway for the directional motion of Li+ ions and at the same time prevent the access of the anions by size exclusion, resulting in good separation of the Li+ ions and the anions. The conductivity of the reported material is 30 times higher than that of the comparable PEO/Li+ complex crystal at room temperature. By using state‐of‐art solid‐state NMR spectroscopy, the structure and dynamics of the material were investigated in detail. The dynamics of the Li+ ions was studied and correlated to the ionic conductivity of the material.
A new category of crystalline polymer electrolyte has been prepared by the supramolecular self‐assembly of PEO (see picture, black), α‐cyclodextrin (α‐CD, blue), and LiAsF6. In this polymer electrolyte, the nanochannels formed by α‐CD provide the pathway for the directional motion of Li+ ions (colored spheres, 5 different environments) and at the same time prevent access of the anions by size exclusion, thereby resulting in good separation of the Li+ ions and the anions.
Background
Gamma‐aminobutyric acid (GABA) is an inhibitory neurotransmitter in human brains, playing a role in the pathogenesis of various psychiatric disorders. Current methods have some ...non‐neglectable shortcomings and noninvasive and accurate detection of GABA in human brains is long‐term challenge.
Purpose
To develop a pulse sequence capable of selectively detecting and quantifying the 1H signal of GABA in human brains based on optimal controlled spin singlet order.
Study Type
Prospective.
Subjects/Phantom
A phantom of GABA (pH = 7.3 ± 0.1) and 11 healthy subjects (5 females and 6 males, body mass index: 21 ± 3 kg/m2, age: 25 ± 4 years).
Field Strength/Sequence
7 Tesla, 3 Tesla, GABA‐targeted magnetic resonance spectroscopy (GABA‐MRS‐7 T, GABA‐MRS‐3 T), magnetization prepared two rapid acquisition gradient echoes sequence.
Assessment
By using the developed pulse sequences applied on the phantom and healthy subjects, the signals of GABA were successfully selectively probed. Quantification of the signals yields the concentration of GABA in the dorsal anterior cingulate cortex (dACC) in human brains.
Statistical Tests
Frequency.
Results
The 1H signals of GABA in the phantom and in the human brains of healthy subjects were successfully detected. The concentration of GABA in the dACC of human brains was 3.3 ± 1.5 mM.
Data Conclusion
The developed pulse sequences can be used to selectively probe the 1H MR signals of GABA in human brains in vivo.
Evidence Level
1
Technical Efficacy Stage
1
Magnetic resonance imaging (MRI) and magnetic resonance spectroscopy (MRS) have made great successes in clinical diagnosis, medical research, and neurological science. MRI provides high resolution ...anatomical images of tissues/organs, and MRS provides information of the functional molecules related to a specific tissue/organ. However, it is difficult for classic MRI/MRS to selectively image/probe a specific metabolite molecule other than the water or fat in tissues/organs. This greatly limits their applications on the study of the molecular mechanism(s) of metabolism and disease. Herein, we report a series of molecularly targeted MRI/MRS methods to target specific molecules. The optimal control method was used to efficiently prepare the singlet spin orders of varied multi-spin systems and in turn greatly expand the choice of the targeted molecules in the molecularly targeted MRI/MRS. Several molecules, such as N-acetyl-L-aspartic acid (NAA), dopamine (DA), and a tripeptide (alanine-glycine-glycine, AGG), have been used as targeted molecules for molecularly targeted MRI and MRS. We show in vivo NAA-targeted
H MRS spectrum of a human brain. The high-resolution signal of NAA suggests a promising way to study important issues in molecular biology at the molecular level, e.g., measuring the local pH value of tissue in vivo, demonstrating the high potential of such methods in medicine.
Most current approaches applied for the essential identification of adulteration in edible vegetable oils are of limited practical benefit because they require long analysis times, professional ...training, and costly instrumentation. The present work addresses this issue by developing a novel simple, accurate, and rapid identification approach based on the magnetic resonance relaxation fingerprints obtained from low-field nuclear magnetic resonance spectroscopy measurements of edible vegetable oils. The relaxation fingerprints obtained for six types of edible vegetable oil, including flaxseed oil, olive oil, soybean oil, corn oil, peanut oil, and sunflower oil, are demonstrated to have sufficiently unique characteristics to enable the identification of the individual types of oil in a sample. By using principal component analysis, three characteristic regions in the fingerprints were screened out to create a novel three-dimensional characteristic coordination system for oil discrimination and adulteration identification. Univariate analysis and partial least squares regression were used to successfully quantify the oil adulteration in adulterated binary oil samples, indicating the great potential of the present approach on both identification and quantification of edible oil adulteration.
The signals of glutamate (Glu) and glutamine (Gln) are often significantly overlapped in routine
H-MR spectra of human brain in vivo. Selectively probing the signals of Glu and Gln in vivo is very ...important for the study of the metabolisms in which Glu and Gln are involved.
The Glu-/Gln- targeted pulse sequences are developed to selectively probe the signals of Glu and Gln. The core part of the Glu-/Gln- targeted pulse sequences lies on the preparation of the nuclear spin singlet orders (SSOs) of the five-spin systems of Glu and Gln. The optimal control method is used to prepare the SSOs of Glu and Gln with high efficiency.
The Glu-/Gln- targeted pulse sequences have been applied on phantoms to selectively probe the signals of Glu and Gln. Moreover, in the in vivo experiments, the signals of Glu and Gln in human brains of healthy subjects have been successfully probed separately.
The developed Glu-/Gln- targeted pulse sequences can be used to distinguish the
H-MR signals of Glu and Gln in human brains in vivo. The optimal control method provides an effective way to prepare the SSO of a specific spin system with high efficiency and in turn selectively probe the signals of a targeted molecule.
A new category of crystalline polymer electrolyte prepared by the supramolecular self‐assembly of polyethylene oxide (PEO), α‐cyclodextrin (α‐CD), and LiAsF6 is reported. The polymer electrolyte ...consists of the nanochannels formed by α‐CDs in which the PEO/Li+ complexes are confined. The nanochannels formed by α‐CD provide the pathway for the directional motion of Li+ ions and at the same time prevent the access of the anions by size exclusion, resulting in good separation of the Li+ ions and the anions. The conductivity of the reported material is 30 times higher than that of the comparable PEO/Li+ complex crystal at room temperature. By using state‐of‐art solid‐state NMR spectroscopy, the structure and dynamics of the material were investigated in detail. The dynamics of the Li+ ions was studied and correlated to the ionic conductivity of the material.
Ein kristalliner Polymerelektrolyt entsteht durch Selbstorganisation von PEO (siehe Bild, schwarz), α‐Cyclodextrin (α‐CD, blau) und LiAsF6. In diesem supramolekularen Elektrolyt öffnen die α‐CD‐Nanokanäle einen Pfad für die gerichtete Bewegung von Li+ (in 5 verschiedenen Umgebungen als bunte Kugeln dargestellt), während sie die größeren Anionen ausschließen.
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•A NMR method having the multiple-targeting signal selectivity was developed.•Optimal control was used to efficiently prepare singlet order of multiple-spin system.•Several targeted ...molecules and/or chemical groups were probed simultaneously.
Selectively probing specific molecules in complex mixtures with nuclear magnetic resonance promises new insights into molecular structures or molecular interaction. Such a study often can be further facilitated when two or more objects in chemical moieties of interest can be precisely targeted. Herein, we proposed a novel method to implement the multiple-targeting signal selection by optimal control of the spin singlets of two or more targeted spin systems from one or more molecules. This method can endow the conventional nuclear magnetic resonance (NMR), magnetic resonance image (MRI) and magnetic resonance spectrum (MRS) with the multiple-targeting signal selectivity to selectively probe several targeted molecules and/or chemical groups simultaneously.
PurposeThe signals of glutamate (Glu) and glutamine (Gln) are often significantly overlapped in routine 1H‐MR spectra of human brain in vivo. Selectively probing the signals of Glu and Gln in vivo is ...very important for the study of the metabolisms in which Glu and Gln are involved.MethodsThe Glu−/Gln‐ targeted pulse sequences are developed to selectively probe the signals of Glu and Gln. The core part of the Glu−/Gln‐ targeted pulse sequences lies on the preparation of the nuclear spin singlet orders (SSOs) of the five‐spin systems of Glu and Gln. The optimal control method is used to prepare the SSOs of Glu and Gln with high efficiency.ResultsThe Glu−/Gln‐ targeted pulse sequences have been applied on phantoms to selectively probe the signals of Glu and Gln. Moreover, in the in vivo experiments, the signals of Glu and Gln in human brains of healthy subjects have been successfully probed separately.ConclusionThe developed Glu−/Gln‐ targeted pulse sequences can be used to distinguish the 1H‐MR signals of Glu and Gln in human brains in vivo. The optimal control method provides an effective way to prepare the SSO of a specific spin system with high efficiency and in turn selectively probe the signals of a targeted molecule.
A new category of crystalline polymer electrolyte prepared by the supramolecular self-assembly of polyethylene oxide (PEO), alpha-cyclodextrin (alpha-CD), and LiAsF sub(6) is reported. The polymer ...electrolyte consists of the nanochannels formed by alpha-CDs in which the PEO/Li super(+) complexes are confined. The nanochannels formed by alpha-CD provide the pathway for the directional motion of Li super(+) ions and at the same time prevent the access of the anions by size exclusion, resulting in good separation of the Li super(+) ions and the anions. The conductivity of the reported material is 30 times higher than that of the comparable PEO/Li super(+) complex crystal at room temperature. By using state-of-art solid-state NMR spectroscopy, the structure and dynamics of the material were investigated in detail. The dynamics of the Li super(+) ions was studied and correlated to the ionic conductivity of the material. A new category of crystalline polymer electrolyte has been prepared by the supramolecular self-assembly of PEO (see picture, black), alpha-cyclodextrin (alpha-CD, blue), and LiAsF sub(6). In this polymer electrolyte, the nanochannels formed by alpha-CD provide the pathway for the directional motion of Li super(+) ions (colored spheres, 5 different environments) and at the same time prevent access of the anions by size exclusion, thereby resulting in good separation of the Li super(+) ions and the anions.
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