6,830 research outputs found

    Quantum Coherence of Image-Potential States

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    The quantum dynamics of the two-dimensional image-potential states in front of the Cu(100) surface is measured by scanning tunneling microscopy (STM) and spectroscopy (STS). The dispersion relation and the momentum resolved phase-relaxation time of the first image-potential state are determined from the quantum interference patterns in the local density of states (LDOS) at step edges. It is demonstrated that the tip-induced Stark shift does not affect the motion of the electrons parallel to the surface.Comment: Submitted to Phys. Rev. Lett., 4 pages, 4 figures; corrected typos, minor change

    Perspectives on joint EANM/SNMMI/ANZSNM practice guidelines/procedure standards for [18F]FDG PET/CT imaging during immunomodulatory treatments in patients with solid tumors

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    Response assessment in the context of immunomodulatory treatments represents a major challenge for the medical imaging community and requires a multidisciplinary approach with involvement of oncologists, radiologists, and nuclear medicine specialists. There is evolving evidence that

    Spectral Analysis Using Regularized Non-Negative Least-Squares Estimation

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    The implementation of spectral analysis techniques involves solving a highly underdetermined linear system equation and is prone to the effect of measurement noise. The authors propose to use a regularized non-negative least-square estimator to stabilize the implementation of the technique. They introduce a penalty term in their formulation of the function to discourage disparities in tracer kinetics between neighboring pixels and use an iterative method to impose positivity constraints. The authors show results from analysis of FDG thorax images of patients suspected to have cancers and summarize their findings.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85892/1/Fessler137.pd

    VEGF released by deferoxamine preconditioned mesenchymal stem cells seeded on collagen-GAG substrates enhances neovascularization

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    Hypoxia preconditioning of mesenchymal stem cells (MSCs) has been shown to promote wound healing through HIF-1 alpha stabilization. Preconditioned MSCs can be applied to three-dimensional biomaterials to further enhance the regenerative properties. While environmentally induced hypoxia has proven difficult in clinical settings, this study compares the wound healing capabilities of adipose derived (Ad) MSCs seeded on a collagen-glycosaminoglycan (GAG) dermal substrate exposed to either environmental hypoxia or FDA approved deferoxamine mesylate (DFO) to stabilize HIF-1 alpha for wound healing. The release of hypoxia related reparative factors by the cells on the collagen-GAG substrate was evaluated to detect if DFO produces results comparable to environmentally induced hypoxia to facilitate optimal clinical settings. VEGF release increased in samples exposed to DFO. While the SDF-1 alpha release was lower in cells exposed to environmental hypoxia in comparison to cells cultured in DFO in vitro. The AdMSC seeded biomaterial was further evaluated in a murine model. The implants where harvested after 1 days for histological, inflammatory, and protein analysis. The application of DFO to the cells could mimic and enhance the wound healing capabilities of environmentally induced hypoxia through VEGF expression and promises a more viable option in clinical settings that is not merely restricted to the laboratory

    VEGF released by deferoxamine preconditioned mesenchymal stem cells seeded on collagen-GAG substrates enhances neovascularization

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    Hypoxia preconditioning of mesenchymal stem cells (MSCs) has been shown to promote wound healing through HIF-1 alpha stabilization. Preconditioned MSCs can be applied to three-dimensional biomaterials to further enhance the regenerative properties. While environmentally induced hypoxia has proven difficult in clinical settings, this study compares the wound healing capabilities of adipose derived (Ad) MSCs seeded on a collagen-glycosaminoglycan (GAG) dermal substrate exposed to either environmental hypoxia or FDA approved deferoxamine mesylate (DFO) to stabilize HIF-1 alpha for wound healing. The release of hypoxia related reparative factors by the cells on the collagen-GAG substrate was evaluated to detect if DFO produces results comparable to environmentally induced hypoxia to facilitate optimal clinical settings. VEGF release increased in samples exposed to DFO. While the SDF-1 alpha release was lower in cells exposed to environmental hypoxia in comparison to cells cultured in DFO in vitro. The AdMSC seeded biomaterial was further evaluated in a murine model. The implants where harvested after 1 days for histological, inflammatory, and protein analysis. The application of DFO to the cells could mimic and enhance the wound healing capabilities of environmentally induced hypoxia through VEGF expression and promises a more viable option in clinical settings that is not merely restricted to the laboratory

    Fifty Years of Fisheries Management m an Obstinate Prairie Lake

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    Little Wall Lake, a shallow 104 ha glacial lake in Hamilton County, Iowa, has been manipulated for about 50 years by fishery managers in an attempt to provide a stable sport fishery. Managers have used dredging, water level manipulation, aquatic vegetation control, mechanical fish removal and fish eradication with toxicants, sport fish stocking, introduction of piscivorous fish, artificial habitat structures, and winter aeration. Attempts to stabilize the fishery have been unsuccessful, and because of overpopulation and stunting of panfishes, total fish eradications were conducted in 1977 and 1989. We review the history of management efforts on the lake, and suggest a series of changes in the habitat and fish community designed to achieve the goal of stabilizing the sport fishery. Proposed management actions include more extensive dredging, more intensive water level manipulations, moderate vegetation control, restrictive harvest regulations on largemouth bass (Micropterus salmoides), and aggressive use and stocking of piscivorous fish (game and non-game species) to prevent overpopulation of panfishes

    Tinnitus as a Measure of Salicylate Toxicity in the Overdose Setting

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    Introduction: The development of tinnitus and/or hearing loss (THL) in patients receiving chronic salicylate therapy has been demonstrated. However, to date, little scientific data validates this relationship in the large single overdose setting.Objective: To correlate salicylate levels in patients with the subjective complaint of THL, following an acute salicylate overdose.Methods: A retrospective chart review of cases of acute salicylate toxicity and THL reported to the Illinois Poison Control Center (IPC) from 2001-2002 was performed. Data abstracted included age, gender, ingestion time, salicylate levels, and arterial blood gases.Results: Ninety-nine cases of THL were reviewed and analyzed with mean age of 23.7 years (SD: 10.9), 30.3% male, and 82.2% intentional overdoses. The average dose ingested was 20.0 grams (SD:20.2) and the mean time from ingestion to medical care was 12.4 hours (SD: 11.1). The mean initial ASA level was 48.3 mg/dl (SD: 16.4) with 86.9% having initial level ≥ 30mg/dl and 40.4% ≥ 50 mg/dl. 85.9% of cases presented to the hospital with their ASA level at or past peak. The mean pH was 7.45, pO2 = 108, pCO2 = 28.0, and HCO3 = 19.9.Conclusion: In this limited study, 85.9% of patients presenting with tinnitus and/or hearing loss following a single salicylate ingestion had initial salicylate levels at or past their peak and 86.9% were in the toxic range

    Effect of Preinjury Oral Anticoagulants on Outcomes Following Traumatic Brain Injury from Falls in Older Adults

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/156128/2/phar2435_am.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/156128/1/phar2435.pd
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