Publications by authors named "Stewart N"

Background: Metastatic intramedullary spinal cord metastases (IMSCMs) constitute <2% of spinal cord tumors. IMSCM is a late-stage manifestation of cancer with a highly variable presentation and poor survival rate. Here, we present an operative video involving gross total resection of an IMSCM (i.

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The aim of this study was to quantify the training effects of wearing calf-loaded wearable resistance (WR) during a netball specific warm-up in female netball athletes. Twenty-nine high school female netball athletes were matched for change of direction (COD) speed and randomly allocated to either WR training or an unloaded group. Both groups performed the same warm-up two times per week for 6 weeks, with the WR group wearing 1%-1.

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Biogenesis of membrane-bound organelles involves the synthesis, remodeling, and degradation of their constituent phospholipids. How these pathways regulate organelle size remains poorly understood. Here we demonstrate that a lipid-degradation pathway inhibits expansion of the endoplasmic reticulum (ER) membrane.

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Introduction: Brain cholesterol relies on de novo biosynthesis and is crucial for brain development. Cholesterol synthesis is a complex series of reactions that involves more than twenty enzymes to reach the final product and generates a large number of intermediate sterols along two alternate pathways. This is a highly regulated and oxygen-dependent process, and thus sensitive to hypoxia.

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AbstractIsland vertebrates that are small on the mainland tend to be larger and exhibit tamer behavior than their mainland conspecifics-a combined set of characteristics known as "island syndrome." Such island-specific traits are often attributed to lower predation pressure on islands than on the mainland. While the morphology and behavior of island vertebrates has received significant attention, relatively few studies have compared physiological traits between island and mainland populations.

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Lung MRI is an important tool in the assessment and monitoring of pediatric and neonatal lung disorders. MRI can provide both similar and complementary image contrast to computed tomography for imaging the lung macrostructure, and beyond this, a number of techniques have been developed for imaging the key functions of the lungs, namely ventilation, perfusion, and gas exchange, through the use of free-breathing proton and hyperpolarized gas MRI. Here, we review the state-of-the-art in MRI methods that have found utility in pediatric and neonatal lung imaging, the structural and physiological information that can be gleaned from such images, and strategies that have been developed to deal with respiratory (and cardiac) motion, and other technological challenges.

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Antibiotic resistance in bacteria is a major global health concern. The wide spread of carbapenemases, bacterial enzymes that degrade the last-resort carbapenem antibiotics, is responsible for multidrug resistance in bacterial pathogens and has further significantly exacerbated this problem. is one of the leading nosocomial pathogens due to the acquisition and wide dissemination of carbapenem-hydrolyzing class D β-lactamases, which have dramatically diminished available therapeutic options.

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Bi-functional enzyme FicD regulates the endoplasmic reticulum chaperone BiP using AMPylation and deAMPylation during ER homeostasis and stress, respectively. Human FicD with an arginine-to-serine mutation disrupts FicD deAMPylation activity resulting in severe neonatal diabetes. We generated the mutation in mice to create a pre-clinical murine model for neonatal diabetes.

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Switchgrass (Panicum virgatum L.) is a North American grass species with biofuel potential. Claviceps spp.

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Article Synopsis
  • The study aimed to evaluate the regional amplitude and phase of dissolved Xe red blood cell signal oscillations in lung blood vessels using a new imaging technique and contrast it with older methods that ignore phase differences.
  • Researchers used a 3D imaging method on 37 participants (including healthy individuals and patients with pulmonary issues) to analyze these oscillations, applying a novel keyhole reconstruction technique to correct for phase differences.
  • Results indicated varying degrees of phase differences among different groups, with improved consistency in oscillation amplitude measurements when adjusted for phase, suggesting potential insights into blood flow dynamics in the lungs.*
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Foundational training in critical care medicine is an integral part of both undergraduate and graduate medical education. Yet, many medical school graduates enter residency underprepared to care for critically ill patients because of a lack of ubiquity of undergraduate critical care education and the heterogeneity of existing didactic and clinical experiences. This Perspective explores the importance of undergraduate critical care education, the current national and international landscape, innovative educational strategies and exemplar curricula, and recent advances in assessment that may better reflect learner-centered educational outcomes.

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Purpose: Three-dimensional hyperpolarized Xe gas exchange imaging suffers from low SNR and long breath-holds, which could be improved using compressed sensing (CS). The purpose of this work was to assess whether gas exchange ratio maps are quantitatively preserved in CS-accelerated dissolved-phase Xe imaging and to investigate the feasibility of CS-dissolved Xe imaging with reduced-cost natural abundance (NA) xenon.

Methods: Xe gas exchange imaging was performed at 1.

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A metal-organic cage (MOC) is shown to be an efficient molecular sponge for PFOS. A large association constant is observed for the 2 : 1 PFOS : MOC host-guest complex. Up to 12 equivalents of PFOS per MOC are removed from water.

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Article Synopsis
  • The synthesis and degradation of phospholipids are crucial for the biogenesis of membrane-bound organelles, specifically in regulating their size.
  • A lipid degradation pathway was identified that inhibits the expansion of the endoplasmic reticulum (ER) membrane, which is influenced by certain enzymes known as phospholipid diacylglycerol acyltransferases (PDATs).
  • The study focused on the yeast PDAT Lro1 and found that its activity can be altered, revealing that active Lro1 not only limits ER membrane expansion but is also regulated by diacylglycerol that affects its distribution and activity.
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Interaction with groundwater determines many processes in marl lakes. Net transfer of inorganic carbon helps define their chemical characteristics and determines their unique benthic flora. Nutrient enrichment weakens the biogeochemical buffering mechanisms which help maintain a clear-water state and many small, shallow marl lakes are prone to siltation.

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During homeostasis, the endoplasmic reticulum (ER) maintains productive transmembrane and secretory protein folding that is vital for proper cellular function. The ER-resident HSP70 chaperone, binding immunoglobulin protein (BiP), plays a pivotal role in sensing ER stress to activate the unfolded protein response (UPR). BiP function is regulated by the bifunctional enzyme filamentation induced by cyclic-AMP domain protein (FicD) that mediates AMPylation and deAMPylation of BiP in response to changes in ER stress.

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Importance: Positive airway pressure (PAP) is the first-line treatment for obstructive sleep apnea (OSA), but evidence on its beneficial effect on major adverse cardiovascular events (MACE) and mortality prevention is limited.

Objective: To determine whether PAP initiation and utilization are associated with lower mortality and incidence of MACE among older adults with OSA living in the central US.

Design, Setting, And Participants: This retrospective clinical cohort study included Medicare beneficiaries with 2 or more distinct OSA claims identified from multistate, statewide, multiyear (2011-2020) Medicare fee-for-service claims data.

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Purpose: To evaluate the feasibility and utility of a deep learning (DL)-based reconstruction for improving the SNR of hyperpolarized Xe lung ventilation MRI.

Methods: Xe lung ventilation MRI data acquired from patients with asthma and/or chronic obstructive pulmonary disease (COPD) were retrospectively reconstructed with a commercial DL reconstruction pipeline at five different denoising levels. Quantitative imaging metrics of lung ventilation including ventilation defect percentage (VDP) and ventilation heterogeneity index (VH) were compared between each set of DL-reconstructed images and alternative denoising strategies including: filtering, total variation denoising and higher-order singular value decomposition.

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Academic physicians are responsible for the education of medical students, residents, and other practicing physicians through clinical rotations lectures, seminars, research, and conferences. Therefore, the increasing need to recruit academic physicians holds immense value within the healthcare system. Academic Medicine Interest Group (AMIG) is a collective made up of students who share an interest in the growth and advancement of academic medicine.

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Purpose: Cancer survival is improving, making optimal management of long-term treatment-related adverse effects increasingly important. Exercise and a healthy diet are beneficial and regularly recommended in cancer survivorship guidelines; however, few cancer survivors meet these recommendations so there is a need to explore why. This study aimed to understand experiences receiving exercise and diet support among Australian breast and prostate cancer survivors during and following treatment, and to explore what support they would like to receive.

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The root nodules of actinorhizal plants are home to nitrogen-fixing bacterial symbionts, known as Frankia, along with a small percentage of other microorganisms. These include fungal endophytes and non-Frankia bacteria. The taxonomic and functional diversity of the microbial consortia within these root nodules is not well understood.

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