111 research outputs found

    Alien Registration- Bradford, Emily H. (Lincoln, Penobscot County)

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    https://digitalmaine.com/alien_docs/7407/thumbnail.jp

    Ground-Penetrating-Radar Reflection Attenuation Tomography with an Adaptive Mesh

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    Ground-penetrating radar (GPR) attenuation-difference analysis can be a useful tool for studying fluid transport in the subsurface. Surface-based reflection attenuation-difference tomography poses a number of challenges that are not faced by crosshole attenuation surveys. We create and analyze a synthetic attenuation-difference GPR data set to determine methods for processing amplitude changes and inverting for conductivity differences from reflection data sets. Instead of using a traditional grid-based inversion, we use a data-driven adaptive-meshing algorithm to alter the model space and to create amore even distribution of resolution. Adaptive meshing provides a method for improving the resolution of the model space while honoring the data limitations and improving the quality of the attenuation difference inversion. Comparing inversions on a conventional rectangular grid with the adaptive mesh, we find that the adaptively meshed model reduces the inversion computation time by an average of 75% with an improvement in the root mean square error of up to 15%. While the sign of the conductivity change is correctly reproduced by the inversion algorithm, the magnitude varies by as much as much as 50% from the true values. Our heterogeneous conductivity model indicates that the attenuation difference inversion algorithm effectively locates conductivity changes, and that surface-based reflection surveys can produce models as accurate as traditional crosshole surveys

    Radiationā€Induced Oral Mucositis Hamster Model Using a Linear Accelerator Enhances Clinical Relevance of Preclinical Studies for Treatment Strategy Investigation

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    Translational animal models for oral mucositis (OM) are necessary to simulate and assess the bioclinical effects and response in humans. These models should simulate high levels of radiation exposure that leads to oxidative stress and inflammatoryā€initiated tissue changes. Hamster models have been extensively studied to observe pathological effects of radiation exposure and help in the development of effective treatments. To successfully evaluate the potential for treatment regimens with consistency and relevance, a radiationā€induced OM hamster model was developed using a clinical linear accelerator utilized by cancer patients daily. The dose exposure to the isolated, everted cheek pouch of a hamster, as well as the progression of injury, proā€inflammatory marker, histological, and elasticity analyses of the buccal pouch were conducted to verify replicability and reproducibility of the injury model. The findings from this model demonstrated its ability to consistently induce injury and resolution over 28 days using an acute dose of 60 Gy. This model was developed to enhance clinical relevance when evaluating potential efficacious treatments and can now be utilized in efficacy studies to better evaluate developed therapeutics in a preclinical model that is easy to translate to clinical studies

    Cancer stem cells: Mediators of tumorigenesis and metastasis in head and neck squamous cell carcinoma

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    BackgroundCancer stem cells (CSCs) represent a subpopulation of cells responsible for tumor growth. Their role in head and neck squamous cell carcinoma (HNSCC) tumorigenesis and metastasis remains uncertain.MethodsWound healing and an orthotopic animal model were used to study cells expressing the CSC phenotype (CD44high and aldehyde dehydrogenase [ALDH]+) and assess mobility, tumorigenesis, and metastasis. A prospective collection of 40 patientā€derived primary HNSCC specimens were analyzed for CSCā€proportion compared to clinical variables.ResultsCSCs exhibited significantly faster wound closure and greater tumorigenesis and regional metastasis in vivo than nonā€CSCs. In primary patient tumors, size and advanced stage were correlated with elevated proportion of CSCs, however, not with survival.ConclusionHNSCC stem cells mediate tumorigenesis and regional metastasis in vivo. In primary patient tumors, CSCā€proportion was associated with tumor size and stage, but not with metastatic spread or survival. CSC burden alone may only represent a minor variable in understanding CSCs and metastasis. Ā© 2014 Wiley Periodicals, Inc. Head Neck 37: 317ā€“326, 2015Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110728/1/hed23600.pd

    A C=Oā‹…ā‹…ā‹…Isothiouronium Interaction Dictates Enantiodiscrimination in Acylative Kinetic Resolutions of Tertiary Heterocyclic Alcohols

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    The research leading to these results has received funding from the ERC under the European Union's Seventh Framework Programme (FP7/2007-2013)/E.R.C. grant agreement nĀ° 279850 and the EPSRC (EP/J500549/1). A.D.S. thanks the Royal Society for a Wolfson Research Merit Award. P.H.-Y.C. is the Bert and Emelyn Christensen Professor and gratefully acknowledges financial support from the Stone Family of OSU. Financial support from the National Science Foundation (NSF) (CHE-1352663) is acknowledged. D.M.W. acknowledges the Bruce Graham and Johnson Fellowships of OSU. D.M.W. and P.H.-Y.C. acknowledge computing infrastructure in part provided by the NSF Phase-2 CCI, Center for Sustainable Materials Chemistry (CHE-1102637).A combination of experimental and computational studies have identified a C=Oā€¢ā€¢ā€¢isothiouronium interaction as key to efficient enantiodiscrimination in the kinetic resolution of tertiary heterocyclic alcohols bearing up to three potential recognition motifs at the stereogenic tertiary carbinol center. This discrimination was exploited in the isothiourea-catalyzed acylative kinetic resolution of tertiary heterocyclic alcohols (38 examples, s factors up to > 200). The reaction proceeds at low catalyst loadings (generally 1 mol %) with either isobutyric or acetic anhydride as the acylating agent under mild conditionsPostprintPeer reviewe

    The National COVID Cohort Collaborative (N3C): Rationale, design, infrastructure, and deployment.

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    OBJECTIVE: Coronavirus disease 2019 (COVID-19) poses societal challenges that require expeditious data and knowledge sharing. Though organizational clinical data are abundant, these are largely inaccessible to outside researchers. Statistical, machine learning, and causal analyses are most successful with large-scale data beyond what is available in any given organization. Here, we introduce the National COVID Cohort Collaborative (N3C), an open science community focused on analyzing patient-level data from many centers. MATERIALS AND METHODS: The Clinical and Translational Science Award Program and scientific community created N3C to overcome technical, regulatory, policy, and governance barriers to sharing and harmonizing individual-level clinical data. We developed solutions to extract, aggregate, and harmonize data across organizations and data models, and created a secure data enclave to enable efficient, transparent, and reproducible collaborative analytics. RESULTS: Organized in inclusive workstreams, we created legal agreements and governance for organizations and researchers; data extraction scripts to identify and ingest positive, negative, and possible COVID-19 cases; a data quality assurance and harmonization pipeline to create a single harmonized dataset; population of the secure data enclave with data, machine learning, and statistical analytics tools; dissemination mechanisms; and a synthetic data pilot to democratize data access. CONCLUSIONS: The N3C has demonstrated that a multisite collaborative learning health network can overcome barriers to rapidly build a scalable infrastructure incorporating multiorganizational clinical data for COVID-19 analytics. We expect this effort to save lives by enabling rapid collaboration among clinicians, researchers, and data scientists to identify treatments and specialized care and thereby reduce the immediate and long-term impacts of COVID-19
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