Reduction of radiofrequency induced implant heating via flexible metasurface shielding at 7 T.

Passive implanted devices are commonly contraindicated at ultra-high field MRI due to the risk of radiofrequency heating. Mitigation of this risk has come in many forms, such as modifying implant materials or creating novel radiofrequency coils. These methods require substantial involvement from manufacturers and may not benefit patients with existing implants.

In Vivo Brain B Inhomogeneity Correction and NOE Image Enhancement at 7 T via Flexible Metasurfaces.

Nuclear Overhauser effect (NOE) MRI has been used for in vivo brain imaging to assess lipid and protein composition and benefits from 7 T field strengths due to the larger chemical shift dispersion. However, a continuing challenge is signal drop off observed in regions such as the medial temporal lobes due to "standing wave" effects from shorter radiofrequency (RF) wavelengths at ultra-high fields. 2D periodic unit cell metasurfaces have been a promising approach for providing improvements in anatomical imaging but have not yet been evaluated in chemical exchange saturation transfer (CEST)-based sequences.

Diffuse nuclear Overhauser effect MRI contrast changes detected in multiple sclerosis subjects at 7T.

Multiple sclerosis is an inflammatory demyelinating condition of the central nervous system affecting approximately 1 million people in the USA. Although standard structural MRI techniques are now the main imaging modality for multiple sclerosis diagnosis and management, they are yet to provide information regarding the metabolic profile of the disease. Ultra-high field 7T MRI systems have provided gains in signal-to-noise ratio (SNR) and spatial resolution for structural MRI as well as larger chemical shifts leading to improvements in specialized imaging sequences, such as nuclear Overhauser effect (NOE) imaging, that can evaluate macromolecular metabolite composition.

Quantification of NAD T and T Relaxation Times Using Downfield H MRS at 7 T in Human Brain In Vivo.

The purpose of this study was to measure T and T relaxation times of NAD proton resonances in the downfield H MRS spectrum in human brain at 7 T in vivo and to assess the propagation of relaxation time uncertainty in NAD quantification. Downfield spectra from eight healthy volunteers were acquired at multiple echo times to measure T relaxation times, and saturation recovery data were acquired to measure T relaxation times. The downfield acquisition used a spectrally selective 90° sinc pulse for excitation centered at 9.

Potassium Nitrate in Heart Failure With Preserved Ejection Fraction: A Randomized Clinical Trial.

Importance: Nitric oxide deficiency may contribute to exercise intolerance in patients with heart failure with preserved ejection fraction (HFpEF). Prior pilot studies have shown improvements in exercise tolerance with single-dose and short-term inorganic nitrate administration.

Objective: To assess the impact of chronic inorganic nitrate administration on exercise tolerance in a larger trial of participants with HFpEF.

High-throughput DNA engineering by mating bacteria.

To reduce the operational friction and scale DNA engineering, we report here an DNA assembly technology platform called SCRIVENER (equential onjugation and ecombination for n ivo longation of ucleotides with low rors). SCRIVENER combines bacterial conjugation, DNA cutting, and homologous recombination to seamlessly stitch blocks of DNA together by mating in large arrays or pools. This workflow is simpler, cheaper, and higher throughput than current DNA assembly approaches that require DNA to be moved in and out of cells at different procedural steps.

Optimization of H-MRS methods for large-volume acquisition of low-concentration downfield resonances at 3 T and 7 T.

Purpose: This goal of this study was to optimize spectrally selective H-MRS methods for large-volume acquisition of low-concentration metabolites with downfield resonances at 7 T and 3 T, with particular attention paid to detection of nicotinamide adenine dinucleotide (NAD) and tryptophan.

Methods: Spectrally selective excitation was used to avoid magnetization-transfer effects with water, and various sinc pulses were compared with a band-selective, uniform response, pure-phase (E-BURP) pulse. Localization using a single-slice selective pulse was compared with voxel-based localization that used three orthogonal refocusing pulses, and low bandwidth refocusing pulses were used to take advantage of the chemical shift displacement of water.

Reliability of In Vivo Creatine-Weighted Chemical Exchange Saturation Transfer (CrCEST) MRI in Calf Skeletal Muscle of Healthy Volunteers at 3 T.

Background: Skeletal muscle mitochondrial oxidative phosphorylation (mtOXPHOS) is important for ATP generation and its dysfunction leads to exercise intolerance. Phosphorus magnetic resonance spectroscopy (P-MRS) is a useful, noninvasive technique for mtOXPHOS assessment but has limitations. Creatine-weighted chemical exchange saturation transfer (CrCEST) MRI is a potential alternative to assess muscle bioenergetics.

Cathodoluminescence from interlayer excitons in a 2D semiconductor heterobilayer.

Photoluminescence has widely been used to study excitons in semiconducting transition metal dichalcogenide (MX) monolayers, demonstrating strong light-matter interactions and locked spin and valley degrees of freedom. In heterobilayers composed of overlapping monolayers of two different MX, an interlayer exciton can form, with the hole localised in one layer and the electron in the other. These interlayer excitons are long-lived, field-tunable, and can be trapped by moiré patterns formed at small twist angles between the layers.

Insulin Sensitivity and Insulin Secretion in Adults With Friedreich's Ataxia: The Role of Skeletal Muscle.

Introduction: Friedreich's ataxia (FRDA) is a multisystem disorder caused by frataxin deficiency. FRDA-related diabetes mellitus (DM) is common. Frataxin supports skeletal muscle mitochondrial oxidative phosphorylation (OXPHOS) capacity, a mediator of insulin sensitivity.

Acute nicotinamide riboside supplementation increases human cerebral NAD levels in vivo.

Purpose: The purpose of this study was to determine the effect of acute nicotinamide riboside (NR) supplementation on cerebral nicotinamide adenine dinucleotide (NAD) levels in the human brain in vivo by means of downfield proton MRS (DF H MRS).

Methods: DF H MRS was performed on 10 healthy volunteers in a 7.0 T MRI scanner with spectrally selective excitation and spatially selective localization to determine cerebral NAD levels on two back-to-back days: once after an overnight fast (baseline) and once 4 h after oral ingestion of nicotinamide riboside (900 mg).

Personalized and muscle-specific OXPHOS measurement with integrated CrCEST MRI and proton MR spectroscopy.

Creatine chemical exchange saturation transfer (CrCEST) MRI is an emerging high resolution and noninvasive method for measuring muscle specific oxidative phosphorylation (OXPHOS). However, CrCEST measurements are sensitive to changes in muscle pH, which might confound the measurement and interpretation of creatine recovery time (τ). Even with the same prescribed exercise stimulus, the extent of acidification and hence its impact on τ is expected to vary between individuals.

NeuroRehabilitation OnLine: Description of a regional multidisciplinary group telerehabilitation innovation for stroke and neurological conditions using the Template for Intervention Description and Replication checklist.

Background: Providing recommended amounts of rehabilitation for stroke and neurological patients is challenging. Telerehabilitation is viable for delivering rehabilitation and an acceptable adjunct to in-person therapy. NeuroRehabilitation OnLine (NROL) was developed as a pilot and subsequently operationalised as a regional innovation embedded across four National Health Service (NHS) Trusts.

Tunnel junctions based on interfacial two dimensional ferroelectrics.

Van der Waals heterostructures have opened new opportunities to develop atomically thin (opto)electronic devices with a wide range of functionalities. The recent focus on manipulating the interlayer twist angle has led to the observation of out-of-plane room temperature ferroelectricity in twisted rhombohedral bilayers of transition metal dichalcogenides. Here we explore the switching behaviour of sliding ferroelectricity using scanning probe microscopy domain mapping and tunnelling transport measurements.

Optimization of H MR spectroscopy methods for large volume acquisition of low concentration downfield resonances at 3T and 7T.

Purpose: This goal of this study was to optimize spectrally selective H MRS methods for large volume acquisition of low concentration metabolites with downfield resonances at 7T and 3T, with particular attention paid to detection of nicotinamide adenine dinucleotide (NAD) and tryptophan.

Methods: Spectrally selective excitation was used to avoid magnetization transfer effects with water, and various sinc pulses were compared to a pure-phase E-BURP pulse. Localization using a single slice selective pulse was compared to voxel-based localization that used three orthogonal refocusing pulses, and low bandwidth refocusing pulses were used to take advantage of the chemical shift displacement of water.

Conduction Band Replicas in a 2D Moiré Semiconductor Heterobilayer.

Stacking monolayer semiconductors creates moiré patterns, leading to correlated and topological electronic phenomena, but measurements of the electronic structure underpinning these phenomena are scarce. Here, we investigate the properties of the conduction band in moiré heterobilayers of WS/WSe using submicrometer angle-resolved photoemission spectroscopy with electrostatic gating. We find that at all twist angles the conduction band edge is the -point valley of the WS, with a band gap of 1.

In vivo enhancement of calf MRI at 7 T via optimized flexible metasurfaces.

Purpose: Ultrahigh field (≥7 T) MRI is at the cutting edge of medical imaging, enabling enhanced spatial and spectral resolution as well as enhanced susceptibility contrast. However, transmit ( ) field inhomogeneity due to standing wave effects caused by the shortened RF wavelengths at 7 T is still a challenge to overcome. Novel hardware methods such as dielectric pads have been shown to improve the field inhomogeneity but are currently limited in their corrective effect by the range of high-permittivity materials available and have a fixed shelf life.

Quantification of NAD T and T relaxation times using downfield H MRS at 7 T in human brain in vivo.

Introduction: The purpose of this study was to use a single-slice spectrally-selective sequence to measure T and T relaxation times of NAD proton resonances in the downfield H MRS spectrum in human brain at 7 T in vivo and assess the propagation of relaxation time uncertainty in NAD quantification.

Methods: Downfield spectra from 7 healthy volunteers were acquired at multiple echo times in all subjects to measure T relaxation, and saturation recovery data were to measure T relaxation. The downfield acquisition used a spectrally-selective 90° sinc pulse for excitation centered at 9.

Frailty and nutrition.

As the ageing population grows and forms a significant category of over 65s in many societies, along with it comes the risk of developing physical and psychological degenerative changes. This presents many challenges for health and social care services in not only identifying those at risk but also managing that risk to try to preserve health and independence for as long as possible. Screening for frailty has supported services to identify those that may be at risk of hospitalisation, requiring long term care or support services at home in older age.

Application of glutamate weighted CEST in brain imaging of nicotine dependent participants in vivo at 7T.

Introduction: With nicotine dependence being a significant healthcare issue worldwide there is a growing interest in developing novel therapies and diagnostic aids to assist in treating nicotine addiction. Glutamate (Glu) plays an important role in cognitive function regulation in a wide range of conditions including traumatic brain injury, aging, and addiction. Chemical exchange saturation transfer (CEST) imaging via ultra-high field MRI can image the exchange of certain saturated labile protons with the surrounding bulk water pool, making the technique a novel tool to investigate glutamate in the context of addiction.

Targeting malnutrition in patients with COPD in the community.

The number of individuals living with chronic obstructive pulmonary disease (COPD) is increasing, but nutritional care can be inconsistent, especially in those with stable COPD. Historically, poor appetite and weight loss have been considered the norm during the progression of COPD into the later stage. However, it is imperative that nutritional assessment, support and management is undertaken from diagnosis, because malnutrition can lead to exacerbations of COPD and increased hospitalisation.

Early-stage mapping of macromolecular content in APP mouse model of Alzheimer's disease using nuclear Overhauser effect MRI.

Non-invasive methods of detecting early-stage Alzheimer's disease (AD) can provide valuable insight into disease pathology, improving the diagnosis and treatment of AD. Nuclear Overhauser enhancement (NOE) MRI is a technique that provides image contrast sensitive to lipid and protein content in the brain. These macromolecules have been shown to be altered in Alzheimer's pathology, with early disruptions in cell membrane integrity and signaling pathways leading to the buildup of amyloid-beta plaques and neurofibrillary tangles.

Implementation of neurological group-based telerehabilitation within existing healthcare during the COVID-19 pandemic: a mixed methods evaluation.

Background: There is a need to evaluate if and how telerehabilitation approaches might co-exist within healthcare in the long-term. Our aim was to implement and evaluate a multidisciplinary group-based telerehabilitation approach for people engaging in neurological rehabilitation.

Methods: NeuroRehabilitation OnLine (NROL) was adapted and implemented within an existing healthcare system as a programme of repeating six-week blocks.