Browsing by Subject "Fractionation"

Now showing 1 - 4 of 4
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    Baseline Karnofsky performance status is independently predictive of death within 30 days of intracranial radiation therapy completion for metastatic disease
    (Elsevier, 2020) McClelland, Shearwood, III.; Agrawal, Namita; Elbanna, May F.; Shiue, Kevin; Bartlett, Gregory K.; Lautenschlaeger, Tim; Zellars, Richard C.; Watson, Gordon A.; Ellsworth, Susannah G.; Radiation Oncology, School of Medicine
    Introduction: For patients with brain metastases, palliative radiation therapy (RT) has long been a standard of care for improving quality of life and optimizing intracranial disease control. The duration of time between completion of palliative RT and patient death has rarely been evaluated. Methods: A compilation of two prospective institutional databases encompassing April 2015 through December 2018 was used to identify patients who received palliative intracranial radiation therapy. A multivariate logistic regression model characterized patients adjusting for age, sex, admission status (inpatient versus outpatient), Karnofsky Performance Status (KPS), and radiation therapy indication. Results: 136 consecutive patients received intracranial palliative radiation therapy. Patients with baseline KPS <70 (OR = 2.2; 95%CI = 1.6-3.1; p < 0.0001) were significantly more likely to die within 30 days of treatment. Intracranial palliative radiation therapy was most commonly delivered to provide local control (66% of patients) or alleviate neurologic symptoms (32% of patients), and was most commonly delivered via whole brain radiation therapy in 10 fractions to 30 Gy (38% of patients). Of the 42 patients who died within 30 days of RT, 31 (74%) received at least 10 fractions. Conclusions: Our findings indicate that baseline KPS <70 is independently predictive of death within 30 days of palliative intracranial RT, and that a large majority of patients who died within 30 days received at least 10 fractions. These results indicate that for poor performance status patients requiring palliative intracranial radiation, hypofractionated RT courses should be strongly considered.
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    Blow fly stable isotopes reveal larval diet: A case study in community level anthropogenic effects
    (PLOS, 2021-04) Owings, Charity G.; Gilhooly, William P. III; Picard, Christine J.; Earth Sciences, School of Science
    Response to human impacts on the environment are typically initiated too late to remediate negative consequences. We present the novel use of stable isotope analysis (SIA) of blow flies to determine human influences on vertebrate communities in a range of human-inhabited environments, from a pristine national park to a dense metropolitan area. The refrain “you are what you eat” applies to the dietary isotope record of all living organisms, and for carrion-breeding blow flies, this translates to the type of carcasses present in an environment. Specifically, we show that carnivore carcasses make up a large proportion of the adult fly’s prior larval diet, which contrasts to what has been reportedly previously for the wild adult fly diet (which consists of mostly herbivore resources). Additionally, we reveal the potential impact of human food on carcasses that were fed on by blow flies, underscoring the human influences on wild animal populations. Our results demonstrate that using SIA in conjunction with other methods (e.g., DNA analysis of flies) can reveal a comprehensive snapshot of the vertebrate community in a terrestrial ecosystem.
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    Occurrences of 2-methylisoborneol and geosmin –degrading bacteria in a eutrophic reservoir and the role of cell-bound versus dissolved fractions
    (Elsevier, 2021-11) Clercin, Nicolas A.; Druschel, Gregory K.; Gray, Mark; Earth Sciences, School of Science
    As taste-and-odor outbreaks are common in surface waters worldwide, extensive studies have focused on the identification of microorganisms involved in the production of 2-methylisoborneol (MIB) and geosmin (GSM). However, fewer studies have tried to identify potential degraders in natural environments. Eagle Creek Reservoir, a temperate and eutrophic water body, experienced two major seasonal odorous outbreaks in 2013 with maximal concentrations of 99.1 (MIB) and 77.3 ng L−1 (GSM). Fractionation analyses of the odorous compounds showed that MIB was found more frequently in the dissolved fraction while GSM was mostly cell-bound. This difference likely impacts taste-and-odor (T&O) compound susceptibility to biodegradation by bacteria. Spearman relationships of epilimnetic samples collected between spring and early fall linked dissolved MIB occurrences to higher abundances of Bacteroidetes like Flavobacterium resistens, F. granuli, F. saliperosum (p < 0.001), F. kamogawaensis (p < 0.01) capable of MIB degradation. Occurrences of cell-bound GSM were correlated to two α-Proteobacteria Novosphingobium hassiacum (p < 0.001) and Sphingomonas oligophenolica (p < 0.01), both identified as potential degraders of GSM. The roles of Pseudomonas and Bacillus were ambiguous, and these genera might have been involved in both compound biodegradations (p < 0.05).