A 3He NMR resonance of C606- containing He is assigned to He2@C606-, thus showing that C60 can also accommodate two helium atoms. The ratio of the di-helium compound relative to the mono- is 1:200, 10 times lower than the equivalent counterpart of C70. The 3He NMR chemical shift of He2@C606- is 0.093 ppm downfield from the already known resonance of He@C606-. In the reduced endohedral mono- and di-helium C70, the 3He NMR chemical shift of He2@C706- is 0.154 ppm upfield from the peak of He@C706-.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1021/ja025990y | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Magnetic-field coils for metastability-exchange optical pumping, spectroscopy, and magnetic resonance of helium.
Rev Sci Instrum
August 2024
Laboratoire Kastler Brossel, ENS-Université PSL, CNRS, Sorbonne Université, Collège de France, 24 rue Lhomond, 75005 Paris, France.
Optical pumping on the 23S-23P transition (1083 nm) of metastable 3He or 4He atoms is used for science and applications. Gas is usually enclosed in elongated cells with lengths ranging from several centimeters to several meters for efficient absorption. Good magnetic-field homogeneity is needed for weak diffusion-induced relaxation and long nuclear magnetic resonance (NMR) signal lifetimes.
View Article and Find Full Text PDFA study of helium-3 nuclear magnetic relaxation mechanism in contact with 20 nm DyF nanoparticles.
J Magn Reson
May 2024
Kazan Federal University, Institute of Physics, Kremlevskaya 18, Kazan 420008, Russian Federation.
The spin kinetics of adsorbed and liquid He in contact with a mixture of LaF (99.67 %) and DyF (0.33 %) 20 nm powders at temperatures of 1.
View Article and Find Full Text PDFMachine Learning and CT Texture Features in Ex-smokers with no CT Evidence of Emphysema and Mildly Abnormal Diffusing Capacity.
Acad Radiol
June 2024
Robarts Research Institute, Western University, 1151 Richmond St N, London, N6A 5B7, Canada (M.S., G.P.); Department of Medical Biophysics, Western University, London, Canada (M.S., G.P.); Division of Respirology, Department of Medicine (D.G.M., G.P.); School of Biomedical Engineering, Western University, London, Canada (G.P.). Electronic address:
Rationale And Objectives: Ex-smokers without spirometry or CT evidence of chronic obstructive pulmonary disease (COPD) but with mildly abnormal diffusing capacity of the lungs for carbon monoxide (DL) are at higher risk of developing COPD. It remains difficult to make clinical management decisions for such ex-smokers without other objective assessments consistent with COPD. Hence, our objective was to develop a machine-learning and CT texture-analysis pipeline to dichotomize ex-smokers with normal and abnormal DL (DL≥75% and DL<75%).
View Article and Find Full Text PDFX-nuclear MRS and MRI on a standard clinical proton-only MRI scanner.
J Magn Reson Open
December 2023
Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States.
In light of the growing interest deuterium metabolic imaging, hyperpolarized C, N, He, and Xe imaging, as well as P spectroscopy and imaging in large animals on clinical MR scanners, we demonstrate the use of a (radio)frequency converter system to allow X-nuclear MR spectroscopy (MRS) and MR imaging (MRI) on standard clinical MRI scanners without multinuclear capability. This is not only an economical alternative to the multinuclear system (MNS) provided by the scanner vendors, but also overcomes the frequency bandwidth problem of some vendor-provided MNSs that prohibit users from applications with X-nuclei of low magnetogyric ratio, such as deuterium (6.536 MHz/Tesla) and N (-4.
View Article and Find Full Text PDFChest MRI and CT Predictors of 10-Year All-Cause Mortality in COPD.
COPD
December 2023
Robarts Research Institute, Western University, London, Canada.
Pulmonary imaging measurements using magnetic resonance imaging (MRI) and computed tomography (CT) have the potential to deepen our understanding of chronic obstructive pulmonary disease (COPD) by measuring airway and parenchymal pathologic information that cannot be provided by spirometry. Currently, MRI and CT measurements are not included in mortality risk predictions, diagnosis, or COPD staging. We evaluated baseline pulmonary function, MRI and CT measurements alongside imaging texture-features to predict 10-year all-cause mortality in ex-smokers with ( = 93; 31 females; 70 ± 9years) and without ( = 69; 29 females, 69 ± 9years) COPD.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!