Microbial reductive dechlorination is a key process in aquifers contaminated with chlorinated ethenes and results in a net mass reduction of organic pollutants. Biodegradation rates in the subsurface are temperature-dependent and may be enhanced by increased groundwater temperatures. This study explores the potential of combining the temperature increase from low-temperature Aquifer Thermal Energy Storage with In Situ Bioremediation (ATES-ISB).
View Article and Find Full Text PDFThis study explores the bioprinting of a smooth muscle cell-only bioink into ionically crosslinked oxidized methacrylated alginate (OMA) microgel baths to create self-supporting vascular tissues. The impact of OMA microgel support bath methacrylation degree and cell-only bioink dispensing parameters on tissue formation, remodeling, structure and strength was investigated. We hypothesized that reducing dispensing tip diameter from 27 G (210m) to 30 G (159m) for cell-only bioink dispensing would reduce tissue wall thickness and improve the consistency of tissue dimensions while maintaining cell viability.
View Article and Find Full Text PDFIn this study, we present a versatile, scaffold-free approach to create ring-shaped engineered vascular tissue segments using human mesenchymal stem cell-derived smooth muscle cells (hMSC-SMCs) and endothelial cells (ECs). We hypothesized that incorporation of ECs would increase hMSC-SMC differentiation without compromising tissue ring strength or fusion to form tissue tubes. Undifferentiated hMSCs and ECs were co-seeded into custom ring-shaped agarose wells using four different concentrations of ECs: 0%, 10%, 20%, and 30%.
View Article and Find Full Text PDFPerfluorooctanesulfonate (PFOS), a toxic anionic perfluorinated surfactant, exhibits variable electrostatic adsorption mechanisms on charge-regulated minerals depending on solution hydrochemistry. This work explores the interplay of multicomponent interactions and surface charge effects on PFOS adsorption to goethite surfaces under flow-through conditions. We conducted a series of column experiments in saturated goethite-coated porous media subjected to dynamic hydrochemical conditions triggered by step changes in the electrolyte concentration of the injected solutions.
View Article and Find Full Text PDFThis study advances a methodology to estimate effective apertures of fractures in glacial tills based on dye tracer infiltration tests and numerical simulations. The approach uses the visible penetration depth of the dye tracer along fracture flow paths as primary information to calculate effective fracture apertures. Further data used in the calculation are the dye tracer input concentration and retardation, the duration of the tracer injection, and the hydraulic gradient applied to control the infiltrating water fluxes.
View Article and Find Full Text PDFCell therapies have gained prominence as a promising therapeutic modality for treating a range of diseases. Despite the recent clinical successes of cell therapy products, very few formal training programs exist for cell therapy manufacturing. To meet the demand for a well-trained workforce, we assembled a team of university researchers and industry professionals to develop an online course on the principles and practice of cell therapy manufacturing.
View Article and Find Full Text PDFPerfluorooctanesulfonate (PFOS) has become a major concern due to its widespread occurrence in the environment and severe toxic effects. In this study, we investigate PFOS sorption on goethite surfaces under different water chemistry conditions to understand the impact of variable groundwater chemistry. Our investigation is based on multiple lines of evidence, including (i) a series of sorption experiments with varying pH, ionic strength, and PFOS initial concentration, (ii) IR spectroscopy analysis, and (iii) surface complexation modeling.
View Article and Find Full Text PDFTo elucidate the pathogenesis of vein of Galen malformations (VOGMs), the most common and most severe of congenital brain arteriovenous malformations, we performed an integrated analysis of 310 VOGM proband-family exomes and 336,326 human cerebrovasculature single-cell transcriptomes. We found the Ras suppressor p120 RasGAP (RASA1) harbored a genome-wide significant burden of loss-of-function de novo variants (2042.5-fold, p = 4.
View Article and Find Full Text PDFElectrokinetic techniques employ direct current electric fields to enhance the transport of amendments in low permeability porous media and have been demonstrated effective for in situ remediation of both organic contaminants and heavy metals. The application of electric potential gradients give rise to coupled chemical, hydraulic and electric fluxes, which are at the basis of the main transport mechanisms: electromigration and electroosmosis. Previous research has highlighted the significant impacts of charge interactions and fluid composition, including temperature-dependent properties such as electrolyte conductivity and density, on these transport phenomena.
View Article and Find Full Text PDFEngineered tissues are showing promise as implants to repair or replace damaged tissues in vivo or as in vitro tools to discover new therapies. A major challenge of the tissue engineering field is the sample preservation and storage until their transport and desired use. To successfully cryopreserve tissue, its viability, structure, and function must be retained post-thaw.
View Article and Find Full Text PDFCollagen-based biomaterials loaded with antimicrobial peptides (AMPs) present a promising approach for promoting wound healing while providing protection against infections. In our previous work, we modified the AMP LL37 by incorporating a collagen-binding domain (cCBD) as an anchoring unit for collagen-based wound dressings. We demonstrated that cCBD-modified LL37 (cCBD-LL37) exhibited improved retention on collagen after washing with PBS.
View Article and Find Full Text PDFHighly transient boundary conditions affect mixing of dissolved solutes in groundwater. An example of these transient boundary conditions occurs at the surface water-groundwater interface, where the water level in rivers can change rapidly due to the operation of hydropower plants, leading to a regime known as hydropeaking. Inspired by this phenomenon, this work studies at laboratory scale the effects of fluctuating surface water bodies on solute transport in aquifers.
View Article and Find Full Text PDFBackground: The neurosurgical workforce in the Caribbean and surrounding countries is largely unknown due to the diversity in cultural, linguistic, political, financial disparities, and colonial history between the countries. About 45 neurosurgeons serve 16 million people in the Caribbean Community and Common Market, a trade alliance including most Caribbean nations. We aimed to understand the current scope of neurosurgical workforce in this region while highlighting any system challenges and potential solutions for upscaling the workforce.
View Article and Find Full Text PDFIntroduction: Traumatic brain injury (TBI) is a significant cause of morbidity and mortality in the Caribbean as well as globally. Within the Caribbean, the prevalence of TBI is approximately 706 per 100,000 persons - one of the highest rates per capita in the world.
Research Question: We aim to assess the economic productivity lost due to moderate to severe TBI in the Caribbean.
Introduction: Global access to electronic medical records (EMRs) continues to grow, however many countries including those within the Caribbean Community (CARICOM) lack access to this system. Minimal research investigating EMR use in this region exists.
Research Question: How does limited EMR access impact neurosurgical care within the CARICOM?
Materials And Methods: The Cochrane Library, EMBASE, Scopus, PubMed/MEDLINE databases, and grey literature were queried for studies addressing this issue within the CARICOM and low- and/or middle-income countries (LMICs).
In human vascular anatomy, blood flows from the heart to organs and tissues through a hierarchical vascular tree, comprising large arteries that branch into arterioles and further into capillaries, where gas and nutrient exchange occur. Engineering a complete, integrated vascular hierarchy with vessels large enough to suture, strong enough to withstand hemodynamic forces, and a branching structure to permit immediate perfusion of a fluidic circuit across scales would be transformative for regenerative medicine (RM), enabling the translation of engineered tissues of clinically relevant size, and perhaps whole organs. How close are we to solving this biological plumbing problem? In this review, we highlight advances in engineered vasculature at individual scales and focus on recent strategies to integrate across scales.
View Article and Find Full Text PDFThe use of electrokinetics (EK) has great potential to deliver reactants in impervious porous media, thus overcoming some of the challenges in the remediation of contaminants trapped in low-permeability zones. In this work we experimentally investigate electrokinetic transport in heterogeneous porous media consisting of a sandy matrix with a target clay inclusion. We demonstrate the efficient EK-delivery of permanganate in the target clay zone (transport velocity 0.
View Article and Find Full Text PDFIntroduction: Opportunities for in-country neurosurgical training are severely limited in LMICs, particularly due to rigorous educational requirements and prohibitive upfront costs.
Research Question: This study aims to evaluate financial barriers aspiring neurosurgeons face in accessing and completing neurosurgical training, specifically in LMICs, in order to determine the barriers to equitable access to training.
Material And Methods: In order to assess the financial costs of accessing and completing neurosurgery residency, an electronic survey was administered to those with the most recent experience with the process: aspiring neurosurgeons, neurosurgical trainees, and recent neurosurgery graduates.
Introduction: Neurological disorders are one of the leading causes of death and disability adjusted life years (DALYs). Efforts have been made to increase the neurosurgical workforce in an attempt to address the global disease burden. Despite these efforts, there continues to be a shortage of neurosurgeons in both high-income countries (HICs) and low-and middle-income countries (LMICs).
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