Publications by authors named "Isaac G"

Background: Low-intensity focused ultrasound (LIFU) is a promising form of non-invasive neuromodulation characterized by a rich parameter space that includes intensity, duration, duty cycle and pulsing strategy. The effect and interaction of these parameters to affect human brain activity is poorly understood. A better understanding of how parameters interact is critical to advance LIFU as a potential therapeutic.

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Article Synopsis
  • The study investigates how focused ultrasound (LIFU) can modify brain responses tied to heartbeat, known as heartbeat evoked potentials (HEP), and focuses on specific brain regions like the insula and dorsal anterior cingulate cortex (dACC).
  • Healthy participants received targeted LIFU while their brain activity (EEG) and heart activity (ECG) were monitored, with the main goal of observing changes in HEP amplitudes.
  • Results showed that LIFU to the posterior insula reduced HEP amplitudes, but it did not alter heart rate or variability, indicating the potential for targeting brain areas to influence interoceptive processing.
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Omics-based biomarker technologies, including metabolic profiling (metabolomics/metabonomics) and lipidomics, are making a significant impact on disease understanding, drug development, and translational research. A wide range of patho-physiological processes involve lipids and monitoring changes in lipid abundance can give valuable insights into mechanisms of drug action, off target pharmacology and toxicity. Here we report changes, detected by untargeted LC-MS, in the plasma lipid profiles of male C57Bl/6JRj mice following the PO and IV administration of the epidermal growth factor receptor (EGFR) inhibitor gefitinib.

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Background: The heartbeat evoked potential (HEP) is a brain response time-locked to the heartbeat and a potential marker of interoceptive processing. The insula and dorsal anterior cingulate cortex (dACC) are brain regions that may be involved in generating the HEP. Low-intensity focused ultrasound (LIFU) is a non-invasive neuromodulation technique that can selectively target sub-regions of the insula and dACC to better understand their contributions to the HEP.

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The untargeted global profiling of endogenous metabolites and lipids has the potential to increase knowledge and understanding in many areas of biology. LC-MS/MS is a key technology for such analyses however, several different LC methodologies, using different mobile phase compositions, are required to cover the diversity in polarity and analyte structure encountered in biological samples. Most notably many lipid screening methods make use of isopropanol (IPA) as a major component of mobile phases employed for comprehensive lipidomic profiling.

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Ketamine is an anaesthetic known to have short but rapid-acting anti-depressant effects; however, the neurobehavioural effects of its prolonged use and its role on the oxytocin system in the gut-brain axis are largely undetermined. Female BALB/c mice were either exposed to the chronic unpredictable mild stress (CUMS) paradigm for 21 days and then treated with ketamine in four doses for 14 days or exposed to CUMS and treated simultaneously in four doses of ketamine during the last two weeks of CUMS exposure. After each dose, the forced swim test was conducted to assess depressive-like behaviour.

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Despite their emerging use, the current understanding of the in-vivo functional mechanisms of Dual Mobility (DM) Total Hip Replacements (THRs) is poor, and current characterisation methodologies are not suitable for the unique function and design of these types of devices. Therefore, the aim of this study was to develop a geometric characterisation methodology to estimate dimensional change across the articulating surfaces of retrieved DM polyethylene liners so that their invivo function may be better understood. The method involves the acquisition of three-dimensional coordinate data from the internal and external surfaces of DM liners.

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Dual mobility (DM) implants are being increasingly used for total hip arthroplasties due to the additional range of motion and joint stability they afford over more traditional implant types. Currently, there are no reported methods for monitoring their motions under realistic operating conditions while in vitro and, therefore, it is challenging to predict how they will function under clinically relevant conditions and what failure modes may exist. This study reports the development, calibration, and validation of a novel inertial tracking system that directly mounts to the mobile liner of DM implants.

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Lipid encapsulated messenger RNA (LNP mRNA) has garnered a significant amount of interest from the pharmaceutical industry and general public alike. This attention has been catalyzed by the clinical success of LNP mRNA for SARS-CoV-2 vaccination as well as future promises that might be fulfilled by the biotechnology pipeline, such as the in vivo delivery of a CRISPR/Cas9 complex that can edit patient cells to reduce levels of low-density lipoprotein. LNP mRNAs are comprised of various chemically diverse molecules brought together in a sophisticated intermolecular complex.

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Lipids play a key role in many biological processes, and their accurate measurement is critical to unraveling the biology of diseases and human health. A high throughput HILIC-based (LC-MS) method for the semiquantitative screening of over 2000 lipids, based on over 4000 MRM transitions, was devised to produce an accessible and robust lipidomic screen for phospholipids in human plasma/serum. This methodology integrates many of the advantages of global lipid analysis with those of targeted approaches.

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The use of hybrid surface technology (HST), applied to the metal surfaces of an ACQUITY™ UPLC™ system and column, designed to mitigate the chelation, poor peak shape and analyte loss seen with acidic phospholipids was investigated. Compared to a conventional system significant improvements in both sensitivity, recovery and peak shape were obtained following UPLC on a CSH C18 column when the HST was used for the analysis of lysophosphatidic acid (LPA), phosphatidic acid (PA), lysophosphatidylserine (LPS), phosphatidylserine (PS), phosphatidylinositol-monophosphates (PIP), ceramide phosphate (CerP) and sphingoid base phosphate (SPBP). The benefits in chromatographic performance provided by the HST were seen particularly at low concentrations of these analytes.

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Total Hip Arthroplasty (THA) is one of the most common and successful surgical interventions. The survivorship at 10 years for the most commonly used systems is over 95%. However, the incidence of revision is usually much higher in the 0-1 year time period following the intervention.

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Article Synopsis
  • This study focuses on using vacuum jacketed columns (VJC) in reversed-phase UHPLC-MS to enhance lipidomic analysis of biological samples like plasma, improving the understanding of lipid dysregulation in diseases.
  • VJC methods showed significant advantages over traditional UHPLC, with a 66% increase in peak capacity, a 34% reduction in peak tailing, and a 30% increase in the number of detectable lipids, along with improved resolution and peak intensity.
  • The results demonstrated excellent reproducibility for lipid intensities in mouse plasma samples, showing variations between 1.8% and 12% without any observed drift, indicating reliability in the analysis.
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Lipids play an essential role in plants, and historically manipulating their levels and composition has been an important target for metabolic engineering. A variety of analytical techniques, many based on mass spectrometry, have been utilized for lipid profiling, but the analysis of complex lipid mixtures still poses significant analytical challenges. Recent advances in technology have revived the supercritical fluid chromatography (SFC) as a promising separation technique for lipid analysis.

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Lipids play an important role in the energy storage, cellular signaling, and pathophysiology of diseases such as cancer, neurodegenerative diseases, infections, and diabetes. Due to high importance of diverse lipid classes in human health and disease, manipulating lipid abundance and composition is an important target for metabolic engineering. The extreme structural diversity of lipids in real biological samples is challenging for analytical techniques due to large difference in physicochemical properties of individual lipid species.

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Root-knot nematode Meloidogyne incognita is among the biotic factors which has greatly affected both the yield and the quality of the tomato crop. The egg parasitic nematode, Purpureocillium lilacinum (Pl) is considered as one of the most promising agents in controlling and overcoming this plant pathogen. The nematicidal effect of the native isolate Pl AUMC 10149 on second stage juvenile's survival and egg hatching of M.

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Environmental change poses a devastating risk to human and environmental health. Rapid assessment of water conditions is necessary for monitoring, evaluating, and addressing this global health danger. Sentinels or biological monitors can be deployed in the field using minimal resources to detect water quality changes in real time, quickly and cheaply.

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Background: The risk factors for and clinical impact of radiolucent lines (RLLs) in cementless total hip arthroplasty remain contentious. The aim of this work was to describe a method of classification that has clinical significance and to identify risk factors.

Methods: A cohort of 288 subjects with unrevised Corail stems (DePuy Synthes, Warsaw, IN) were reviewed with radiographs and Oxford Hip Scores at 10 years.

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Metabolomics is a powerful phenotyping platform with potential for high-throughput analyses. The primary technology for metabolite profiling is mass spectrometry. In recent years, the coupling of mass spectrometry with ion mobility spectrometry (IMS) has offered the promise of faster analysis time and greater resolving power.

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One of the most drastic diseases causing economic losses in sunflower crops is fusarium root rot caused by Fusarium solani. Plant extracts and ionizing radiation provide alternative environmentally safe control agents that have a significant role in controlling and overcoming this fungal plant pathogen. In the present study, the effect of different concentrations of aqueous Chenopodium album extract (2.

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Objective: To assess the diagnostic performance of breast magnetic resonance (MR) imaging as a function of gadolinium contrast dose using a retrospective reader study.

Material And Methods: IRB approval was obtained prior to the start of this study and was HIPAA compliant. One-hundred and fifty MR breast examinations were included that were acquired between January 2001 and December 2006.

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The most important tools in killing and overcoming on the microbes and pathogens that cause diseases in medicine and/or in agriculture are the antibiotics. The discovery and synthesis of the microbial natural products or antibiotics has greatly developed genetically and biotechnologically quickly in the last decades. It is necessary to access this great genetic diversity by finding ways to increase the level of expression of these biosynthetic pathways.

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Background: In our current digital age, textbooks have been supplemented or supplanted by multiple online modalities for knowledge acquisition. Trainees, often from a younger generation than their program directors (PDs), prefer options such as podcasts, videos, and question banks. We sought to identify whether an exists between PDs and trainees regarding what is assigned and what is used.

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Article Synopsis
  • Molecular networking is a technique used to analyze and visualize chemical compounds in non-targeted mass spectrometry data.
  • Feature-based molecular networking (FBMN) is a new analysis method within the GNPS framework that improves the detection and organization of chemical features.
  • FBMN allows for better quantitative analysis and differentiation of isomers, including those examined through ion mobility spectrometry.
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