NMR-MRI/S Science Highlights
Scientists can now observe lithium moving through an electrolyte in real time.
High-resolution brain imaging provides evidence of depression, anxiety in diseased mice
Scientists using an MRI-friendly oxygen isotope have demonstrated a promising and safe method for identifying cancerous tumors.
Using an advanced technique, scientists discover that one of the most common substances in our everyday lives — glass — is more complex than we thought.
Scientists gain new insights into how protective shells form around retrovirus genomes, advancing the search for drugs that will combat them.
Inspired by the SIM card technology used in modern cell phones, MagLab engineers designed and built a versatile magnet probe that makes it easier and more efficient for scientists to see the structure of molecules.
Ten years ago the 900 Ultra-Wide Bore magnet became available to an international user community for Nuclear Magnetic Resonance spectroscopy and Magnetic Resonance Imaging at the National High Magnetic Field Lab. Since then 69 publications have been published from this instrument spanning many disciplines and the number of publications per year continues to increase with 26 in just the past 18 months demonstrating that state of the art data continues to be collected on this superb magnet.
Dynamic nuclear polarization (DNP) coupled with solid state NMR can provide orders of magnitude enhancement to normally weak NMR signals, thereby enabling the study of inherently dilute proteins such as membrane proteins. Here we demonstrate a new approach to obtain DNP signal enhancements of membrane proteins by utilizing spin labeled lipids as the polarization agents. This strategy results in more than 2x in signal enhancements of a membrane protein when compared to standard DNP sample preparation techniques.
CrgA, a key Mycobacterium tuberculosis cell division protein that recruits five other proteins to the cell division apparatus has been structurally characterized using oriented sample and magic angle spinning solid state NMR. The protein has two transmembrane helices and an intrinsically disordered N-terminus. Binding sites have been identified for it's binding partners. Evaluating these binding sites may lead to effective drugs for either promoting and inhibiting cell division, both of which are of prime interest for the treatment of tuberculosis.
By coupling selective band excitation of metabolites with high magnetic fields, relaxation-enhanced 1H MR spectroscopy can be performed in living specimen and patients to achieve high sensitivity over very short acquisition times for the examination of cellular dysfunction. This sensitivity can be used to evaluate otherwise inaccessible metabolites or regions of the proton spectral regime and can be used to probe cell-specific environments, such as neurons versus astrocytes, that may undergo differential changes during dysregulation.
Targeted theranostic nanovehicles are capable of targeting cerebrovascular amyloid associated with Alzheimer’s Disease and serving as early diagnostic and therapeutic agents across multiple imaging modalities. Assessed in animal models at 21.1 T, these nanovehicles were loaded with gadolinium-based magnetic resonance imaging (MRI), iodine-based single photon emission computerized tomography (SPECT) or fluorescent contrast agents as well as anti-inflammatory and anti-amyloidogenic pharmaceuticals to demonstrate targeted enhancement and treatment in cerebral amyloid angiopathy.
Structures of antimicrobial peptides piscidins 1 and 3 were solved in two bacterial cell mimics by oriented sample solid-state NMR. A significant finding of this work is that in contrast to the ideal structures shown in mechanistic studies of AMPs, the structures of both peptides are disrupted and kinked at a conserved central glycine, which results in stronger interactions with the lipid bilayers. The more pronounced imperfect amphipathicity of piscidin 1 over piscidin 3 that is revealed helps better understand why the former more effectively mixes the lipids as needed to induce the greatest damage to bacterial cells.
Solid state NMR measurements reveal an important structural distinction between different disease-relevant aggregates: oligomers and fibrils. While molecular confirmations are similar within both structures, oligomers differ from fibrils in terms of intermolecular organization of beta-strands.
Using the lab’s 21 tesla magnet to image chlorine in the brain, researchers explore new ways to track tumor growth.
Using a novel NMR approach, scientists characterize the metabolome of E. coli cells, determining 112 topologies of unique metabolites from a single sample.
Magnetic resonance imaging (MRI) of solid materials entails numerous problems from short longitudinal relaxation (T2) times to requiring strong gradients to attain high resolution images. A promising technique to address these issues is the Stray Field Imaging (STRAFI) method.
Biomedical researchers have a unique tool to investigate a variety of living and excised specimen with the MagLab’s 21.1 T 900-MHz ultra-widebore (105-mm) vertical magnet. However, there are challenges to performing research in a high-field vertical magnet, which have been addressed by a NHMFL-led team of international scientists working to make very high field or ultra high field MRI more flexible. This team has constructed a tunable sliding ring transmit/receive volume coil for 900-MHz hydrogen MRI that provides the uniformity and sensitivity for high resolution and functional imaging of living samples while accommodating unique excised samples to improve characterization and throughput. This new design incorporates the apparatus necessary for maintaining animals in a vertical position while providing remote tuning and sample flexibility beyond most available coils.