Publications by authors named "FAGAN J"

Aqueous two-phase extraction (ATPE) is an effective and scalable liquid-phase processing method for purifying single species of single-wall carbon nanotubes (SWCNTs) from multiple species mixtures. Recent metrological developments have led to advances in the speed of identifying solution parameters leading to more efficient ATPE separations with greater fidelities. In this feature article, we review these developments and discuss their vast potential to further advance SWCNT separations science towards the optimization of production scale processes and the full realization of SWCNT-enabled technologies.

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Recombinant adeno-associated virus (AAV) is one of the main viral vector-based gene therapy platforms. AAV is a virus consisting of a ≈25 nm diameter capsid with a ≈4.7 kb cargo capacity.

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A combination of analytical ultracentrifugation (AUC) and fluorescence spectroscopy are utilized to orthogonally probe compositions of adsorbed surfactant layers on the surface of (7,5) species single-wall carbon nanotubes (SWCNTs) under conditions known to achieve differential partitioning in aqueous two-phase extraction (ATPE) separations. Fluorescence emission intensity and AUC anhydrous particle density measurements independently probe and can discriminate between adsorbed surfactant layers on a (7,5) nanotube comprised of either of two common nanotube dispersants, the anionic surfactants sodium deoxycholate and sodium dodecyl sulfate. Measurements on dispersions containing mixtures of both surfactants indicate near total direct exchange of the dominant surfactant species adsorbed to the carbon nanotube at a critical concentration ratio consistent with the ratio leading to partitioning change in the ATPE separation.

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Partitioning nanoparticles by shape and dimension is paramount for advancing nanomaterial standardization, fundamental colloidal investigations, and technologies such as biosensing and digital electronics. Length-separation methods for single-walled carbon nanotubes (SWCNTs) have historically incurred trade-offs in precision and mass throughput, and boron nitride nanotubes (BNNTs) are a rapidly emerging material analogue. We extend and detail a polymer precipitation-based method to fractionate populations of either nanotube type at significant mass scale for four distinct nanotube sources of increasing average diameter (0.

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Recent advancements in materials science have shed light on the potential of exploring hierarchical assemblies of molecules on surfaces, driven by both fundamental and applicative challenges. This field encompasses diverse areas including molecular storage, drug delivery, catalysis, and nanoscale chemical reactions. In this context, the utilization of nanotube templates (NTs) has emerged as promising platforms for achieving advanced one-dimensional (1D) molecular assemblies.

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Article Synopsis
  • Nanofluidic channels create extreme confinement for water and ions, influencing transport phenomena based on the interactions with channel walls.
  • Researchers found that metallic carbon nanotubes enhance water and proton transport more than semiconducting ones, while ion transport is not significantly affected by the nanotube's electronic properties.
  • Simulations reveal that the unique polarizability of carbon nanotubes plays a key role in these transport processes, highlighting the intricate relationship between electronic properties and transport efficiency in nanoscale environments.
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A significant advance in rate and precision of identifying the co-surfactant concentrations leading to differential extraction of specific single-wall carbon nanotube (SWCNT) species in aqueous two-polymer phase extraction experiments is reported. These gains are achieved through continuous titration of co-surfactant and other solution components during automated fluorescence measurements on SWCNT dispersions. The resulting fluorescence concentration curves display intensity and wavelength shift transitions traceable to the nature of the adsorbed surfactant layer on specific SWCNT structures at the (,) species and enantiomer level at high resolution.

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Background: The Ehlers-Danlos syndromes (EDS) are a group of inherited connective tissue disorders characterized by disruptions in collagen synthesis and processing. These disorders lead to various symptoms, including hypermobility, musculoskeletal conditions, and chronic pain that can significantly limit patients' daily living. In the absence of a curative treatment, an EDS specific disability index that tracks changes in patient-reported outcomes can facilitate the investigation of new treatment options and enhance the quality of life for EDS patients.

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People with human immunodeficiency virus (PWH) are disproportionately affected by depression, but the recent national estimates for US PWH encompassing both current symptoms and clinical diagnoses to assess missed diagnoses and lack of symptom remission are lacking. We used data from CDC's Medical Monitoring Project (MMP) to report nationally representative estimates of diagnosed and undiagnosed depression among US adult PWH. During June 2021 to May 2022, MMP collected interview data on symptoms consistent with major or other depression and depression diagnoses from medical records of 3928 PWH.

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Although multiple domains of risk are theorized to predict adolescent delinquency, father-specific risk in the context of other risks is under-researched. Using the low-income Future of Families and Child Wellbeing cohort (48% Black, 27% Hispanic, 21% White, 51% boy, = 4,255), the current study addressed three research questions. (1) are father-, mother-, child-, and family-level cumulative risk during early childhood associated with adolescent delinquent behavior?, (2) does child self-control in middle childhood mediate the associations between fathers' and mothers' cumulative risk and adolescent delinquent behavior, and do quality of parent's relationships with children and parental monitoring in middle childhood mediate the association between child cumulative risk and delinquent behavior?, (3) do parenting, quality of parent-child relationships in middle childhood, and child sex at birth moderate the associations among fathers', mothers', children's, and family risk and adolescent delinquent behavior? Results indicated father, child, and mother risk at ages 3-5 were significantly and positively associated with youth-reported delinquent behavior.

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Background: The COVID-19 pandemic disrupted postgraduate certification examinations globally. The Colleges of Medicine of South Africa continued hosting certification examinations through the pandemic. This was achieved by effecting a rapid transition from in-person to web-based certification examinations.

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Purpose Of Review: With an increased need to decentralize and train more head and neck ablative and reconstructive surgeons in sub-Saharan Africa, we assess the realities and challenges of free flap reconstruction in sub-Saharan Africa to provide context of its use as a reconstructive option.

Recent Findings: Head and neck free flap reconstruction has been performed by local teams as well as visiting teams in Sub Saharan Africa with good results. Free flap success rates are similar to high income regions at 89% vs.

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Lactococcus spp. are applied routinely in dairy fermentations and their consistent growth and associated acidification activity is critical to ensure the quality and safety of fermented dairy foods. Bacteriophages pose a significant threat to such fermentations and thus it is imperative to study how these bacteria may evade their viral predators in the relevant confined settings.

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Importance: A core component of delivering care of head and neck diseases is an adequate workforce. The World Health Organization report, Multi-Country Assessment of National Capacity to Provide Hearing Care, captured primary workforce estimates from 68 member states in 2012, noting that response rates were a limitation and that updated more comprehensive data are needed.

Objective: To establish comprehensive workforce metrics for global otolaryngology-head and neck surgery (OHNS) with updated data from more countries/territories.

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Fungal parotitis is rare and the sequela parotid abscess exceedingly so. We report our experience with and parotid gland abscesses in critically ill HIV-positive patients and highlight the value of microbiological assessment to tailor management.

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Previous immunological studies in the eastern USA have failed to establish a direct connection between Paleoamericans and extinct megafauna species. The lack of physical evidence for the presence of extinct megafauna begs the question, did early Paleoamericans regularly hunt or scavenge these animals, or were some megafauna already extinct? In this study of 120 Paleoamerican stone tools from across North and South Carolina, we investigate this question using crossover immunoelectrophoresis (CIEP). We find immunological support for the exploitation of extant and extinct megafauna, including Proboscidea, Equidae, and Bovidae (possibly Bison antiquus), on Clovis points and scrapers, as well as possible early Paleoamerican Haw River points.

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Purpose Of Review: Open access articles are more frequently read and cited, and hence promote access to knowledge and new advances in healthcare. Unaffordability of open access article processing charges (APCs) may create a barrier to sharing research. We set out to assess the affordability of APCs and impact on publishing for otolaryngology trainees and otolaryngologists in low-income and middle-income countries (LMICs).

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The Raman excitation spectra of chirality-pure (6,5), (7,5), and (8,3) single-walled carbon nanotubes (SWCNTs) are explored for homogeneous solid film samples over broad excitation energy and scattering energy ranges using a rapid and relatively simple full spectrum Raman excitation mapping technique. Identification of variation in scattering intensity with sample type and phonon energy related to different vibrational bands is clearly realized. Excitation profiles are found to vary strongly for different phonon modes.

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Treatment as prevention (TasP) is an effective HIV prevention strategy. Our objectives were to explore TasP attitudes and beliefs among people with HIV (PWH) who are not engaged in care and to examine attitudes and beliefs by selected characteristics. We sampled PWH who had participated in the Medical Monitoring Project (MMP), a structured interview survey, from June 2018-May 2019 to participate in 60-minute semi-structured telephone interviews.

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Purpose: The proportion of head and neck cancers (HNCs) with human papillomavirus (HPV) positivity in sub-Saharan Africa (SSA) is poorly characterized. Characterizing this has implications in staging, prognosis, resource allocation, and vaccination policies. This study aims to determine the proportion of HPV-associated HNC in SSA.

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Quantitative determination of the effects of surfactant chemistry and polymer chain length on the concentration conditions necessary to yield extraction of specific single-wall carbon nanotube (SWNCT) species in an aqueous two-polymer phase extraction (ATPE) separation are reported. In particular, the effects of polyethylene glycol (PEG) chain length, surfactant ratios, and systematic structural variations of alkyl surfactants and bile salts on the surfactant ratios necessary for extraction were investigated using a recently reported fluorescence-based method. Alkyl surfactant tail length was observed to strongly affect the amount of surfactant necessary to cause PEG-phase extraction of nanotube species in ATPE, while variation in the anionic sulfate/sulfonate head group chemistry has less impact on the concentration necessary for extraction.

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