A5013262324- Atomic and Subatomic Physics Research
- Advanced MRI Techniques and Applications
- NMR spectroscopy and applications
- Quantum, superfluid, helium dynamics
- Advanced NMR Techniques and Applications
- Advanced Neuroimaging Techniques and Applications
- Granular flow and fluidized beds
- Functional Brain Connectivity Studies
- Nuclear Physics and Applications
- Cold Atom Physics and Bose-Einstein Condensates
- Hydrocarbon exploration and reservoir analysis
- Dementia and Cognitive Impairment Research
- Memory and Neural Mechanisms
- Spectroscopy and Laser Applications
- Mineral Processing and Grinding
- Laser Design and Applications
- Memory Processes and Influences
- Magnetic and Electromagnetic Effects
- Hydraulic Fracturing and Reservoir Analysis
- Cultural Differences and Values
- Visual Attention and Saliency Detection
- Face Recognition and Perception
- Agricultural Engineering and Mechanization
- Surfactants and Colloidal Systems
- Health, Environment, Cognitive Aging
Athinoula A. Martinos Center for Biomedical Imaging
2015-2025
Massachusetts General Hospital
2015-2025
Harvard University
2002-2025
Harvard University Press
2019-2024
Center for Pain and the Brain
2023
Center for Astrophysics Harvard & Smithsonian
2000-2009
Massachusetts Institute of Technology
2002-2007
Massey University
1996-1999
The goal of the Brain Genomics Superstruct Project (GSP) is to enable large-scale exploration links between brain function, behavior, and ultimately genetic variation. To provide broader scientific community data probe these associations, a repository structural functional magnetic resonance imaging (MRI) scans linked information was constructed from sample healthy individuals. initial release, detailed in present manuscript, encompasses quality screened cross-sectional 1,570 participants...
Individual differences in human brain aging are difficult to estimate over short intervals because of measurement error. Using a cluster scanning approach that reduces error by densely repeating rapid structural scans, we measured individuals one year. Expected between young and older were evident, as cognitively unimpaired impaired individuals. Each person's change trajectory was compared modeled expectations from large cohort age-matched UK Biobank participants. Cognitively variably...
We show that gas diffusion nuclear magnetic resonance (GD-NMR) provides a powerful technique for probing the structure of porous media. In random packs glass beads, using both laser-polarized and thermally polarized xenon gas, we find GD-NMR can accurately measure pore space surface-area--to--volume ratio, $S/{V}_{p}$, tortuosity, $\ensuremath{\alpha}$ (the latter quantity being directly related to system's transport properties). also good tortuosity sandstone complex carbonate rocks.
A three-dimensional granular system fluidized by vertical container vibrations was studied using pulsed field gradient NMR coupled with one-dimensional magnetic resonance imaging. The consisted of mustard seeds vibrated vertically at 50 Hz, and the number layers ${N}_{\mathcal{l}}<~4$ sufficiently low to achieve a nearly time-independent fluid. Using NMR, profiles density temperature were directly measured, along distributions horizontal grain velocities. velocity showed modest deviations...
We report an observation of shear-banding, under Couette flow, the worm-like surfactant system cetyl pyridinium chloride/sodium salicylate (respective concentrations 100 mM and 60 in pure water). The method, based on NMR velocity imaging, allows direct measurement velocity, consequent calculation shear rate, at a spatial resolution around 10 μm, sufficient to resolve apparent slip inner wall from banding within bulk fluid. Above critical rate (around 1 s−1) high band is observed annulus...
Magnetic resonance imaging of hyperpolarized nuclei provides high image contrast with little or no background signal. To date, in vivo applications prehyperpolarized materials have been limited by relatively short nuclear spin relaxation times. Here, we investigate silicon nanoparticles as a new type magnetic agent. Nuclear times for variety Si are found to be remarkably long, ranging from many minutes hours at room temperature, allowing transported, administered, and imaged on practical...
Prior work has shown Americans have higher levels of memory specificity than East Asians. Neuroimaging studies not investigated mechanisms that account for cultural differences at retrieval. In this study, we use fMRI to assess whether mnemonic discrimination, distinguishing novel from previously encountered stimuli, accounts in memory. Fifty-five American and 55 Taiwanese young adults completed an object recognition paradigm testing discrimination old targets, similar lures foils. Mnemonic...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation R. W. Mair, P. T. Callaghan; Shear flow of wormlike micelles in pipe cylindrical Couette geometries as studied by nuclear magnetic resonance microscopy. J. Rheol. 1 July 1997; 41 (4): 901–924. https://doi.org/10.1122/1.550864 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley...
NMR images of laser polarized ${}^{3}\mathrm{He}$ gas were obtained at 21 G using a simple, homebuilt instrument. At such low fields magnetic resonance imaging (MRI) thermally samples (e.g., water) is not practical. Low-field noble MRI has novel scientific, engineering, and medical applications. Examples include portable systems for diagnosis lung disease, as well voids in porous media within metallic systems.
We have used an NMR technique to measure the short-time, three-dimensional displacement of grains in a system mustard seeds vibrated vertically at 15 g. The averages over time interval which move ballistically, giving direct measurement granular temperature profile. dense, lower portion sample is well described by recent hydrodynamic theory for inelastic hard spheres. Near free upper surface mean path longer than particle diameter and description fails.
Silicon nanoparticles are experimentally investigated as a potential hyperpolarized, targetable MRI imaging agent. Nuclear T_1 times at room temperature for variety of Si found to be remarkably long (10^2 10^4 s) - roughly consistent with predictions core-shell diffusion model allowing them transported, administered and imaged on practical time scales without significant loss polarization. We also report surface functionalization nanoparticles, comparable approaches used in other...
T1-weighted structural MRI is widely used to measure brain morphometry (e.g., cortical thickness and subcortical volumes). Accelerated scans as fast one minute or less are now available but it unclear if they adequate for quantitative morphometry. Here we compared the measurement properties of a adopted 1.0 mm resolution scan from Alzheimer's Disease Neuroimaging Initiative (ADNI = 5'12'') with two variants highly accelerated (compressed-sensing, CSx6 1'12''; wave-controlled aliasing in...
Abstract Regional brain atrophy estimated from structural magnetic resonance imaging (MRI) is a widely used measure of neurodegeneration in Alzheimer’s disease (AD), Frontotemporal Lobar Degeneration (FTLD), and other dementias. Yet, traditional MRI-derived morphometric estimates are susceptible to measurement errors, posing challenge for reliably detecting longitudinal atrophy, particularly over short intervals. Here, we examined the utility multiple MRI scans acquired rapid succession...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation M. Britton, R. W. Mair, K. Lambert, P. T. Callaghan; Transition to shear banding in pipe Couette flow of wormlike micellar solutions. Journal Rheology 1 July 1999; 43 (4): 897–909. https://doi.org/10.1122/1.551008 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote...
Research on molluscan specimens is increasingly being carried out using high-throughput molecular techniques. Due to their efficiency, these technologies have effectively resulted in a strong bias towards genotypic analyses. Therefore, the future large-scale correlation of such data with phenotype will require significant increase output morphological studies. Three-dimensional (3D) scanning techniques as magnetic resonance imaging (MRI) or computed tomography (CT) can achieve this goal they...
While human vision spans 220°, traditional functional MRI setups display images only up to central 10-15°. Thus, it remains unknown how the brain represents a scene perceived across full visual field. Here, we introduce method for ultra-wide angle and probe signatures of immersive representation. An unobstructed view 175° is achieved by bouncing projected image off angled-mirrors onto custom-built curved screen. To avoid perceptual distortion, scenes are created with wide field-of-view from...
We demonstrate a minimally invasive nuclear magnetic resonance (NMR) technique that enables determination of the surface-area-to-volume ratio (S/V) soft porous materials from measurements diffusive exchange laser-polarized 129Xe between gas in pore space and dissolved solid phase. apply this NMR to polymer samples find approximate agreement with destructive stereological S/V obtained optical confocal microscopy. Potential applications xenon interphase include vivo lung function humans...