Publications by authors named "Michael Timmer"
Article Synopsis
- Financial toxicity, especially linked to unemployment, has a significant impact on cancer survivors, prompting an evaluation of how it relates to patient-reported outcomes (PROs) in individuals with primary CNS tumors (PCNST).
- The study, conducted between September 2016 and December 2019 with 277 participants, revealed that Hispanic individuals faced higher unemployment rates and reported greater functional impairments and reduced health-related quality of life (HRQOL) than employed counterparts.
- Unemployed participants exhibited notably higher levels of depressive (25% vs. 8%) and anxiety symptoms (30% vs. 15%), highlighting the mental health challenges associated with unemployment in this patient group.
Article Synopsis
- The study focused on the importance of clinical outcomes assessments (COAs) for patients with malignant glioma, specifically looking at symptoms and functions recommended by the RANO-PRO Working Group.
- Using a cohort of 336 patients from a larger study, researchers analyzed how symptoms like pain and cognitive issues and functions like weakness and ability to work relate to disease progression over time.
- Findings suggest that these COAs are relevant indicators of disease status and may change as the disease progresses, providing vital information for both clinical care and research.
Article Synopsis
- Cognitive impairments are common in patients with primary CNS tumors, and traditional neuropsychological assessments are often too lengthy for routine use, prompting the study of the brief Montreal Cognitive Assessment (MoCA) during in-person and telehealth visits.
- The study involved 71 adults with CNS tumors who took the MoCA, revealing an average score of 25 in-person and 26 via telehealth, with a notable percentage scoring abnormally; satisfaction surveys indicated healthcare providers found the MoCA useful in both settings.
- Findings demonstrated a correlation between lower MoCA scores and worse symptoms, emphasizing the importance of incorporating both objective cognitive measures and patient-reported outcomes for a comprehensive understanding of patient cognition in neuro-oncology care.
Introduction: Despite an increasing aging population, older adults (≥ 65 years) with primary brain tumors (PBTs) are not routinely assessed for geriatric vulnerabilities. Recent reports of geriatric assessment (GA) in patients with glioblastomas demonstrated that GA may serve as a sensitive prognosticator of overall survival. Yet, current practice does not include routine evaluation of geriatric vulnerabilities and the relevance of GA has not been previously evaluated in broader cohorts of PBT patients.
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- Primary CNS tumors lead to significant symptoms and a poor prognosis, prompting a study on long-term survivors (≥5 years) to evaluate their reported outcomes.
- Data from 248 adult survivors revealed that while 42% reported no moderate-to-severe symptoms, many experienced issues like fatigue and cognitive difficulties, with significant anxiety and depression reported by some.
- The study highlights the need for tailored survivorship care programs, as survivors exhibited diverse symptom experiences regardless of tumor characteristics, indicating ongoing support and research are essential.
Implementing a bidirectional impulse turbine into a thermoacoustic refrigerator.
J Acoust Soc Am
September 2020
A thermoacoustic model is used to efficiently implement a bidirectional impulse turbine into a thermoacoustic refrigerator. Experiments are done for several gas types and mean pressures to identify its influence on the turbine efficiency. A scaling is investigated in an attempt to provide a unique function of the turbine efficiency for all operating conditions.
View Article and Find Full Text PDFThe design of a bidirectional impulse turbine to convert thermoacoustic power into electricity is experimentally optimized. The turbine efficiency is measured for rotors with and without a shroud ring and for a varying tip clearance. Furthermore, the axial spacing between the guide vanes and rotor is varied with respect to the displacement amplitude of the acoustic wave.
View Article and Find Full Text PDFCharacterization of bidirectional impulse turbines for thermoacoustic engines.
J Acoust Soc Am
November 2019
A bidirectional impulse turbine to convert thermoacoustic power into electricity is investigated. Experimental measurements are done with a loudspeaker for varying acoustic conditions and turbine loads. The results are used to characterize the turbine performance and compare it to steady flow turbomachinery and turbines in oscillating water columns.
View Article and Find Full Text PDFThermoacoustic engines convert heat energy into high amplitude acoustic waves and subsequently into electric power. This article provides a review of the four main methods to convert the (thermo)acoustic power into electricity. First, loudspeakers and linear alternators are discussed in a section on electromagnetic devices.
View Article and Find Full Text PDFThe design of compact thermoacoustic devices requires compact jet pump geometries, which can be realized by employing jet pumps with multiple orifices. The oscillatory flow through the orifice(s) of a jet pump generates asymmetric hydrodynamic end effects, which result in a time-averaged pressure drop that can counteract Gedeon streaming in traveling wave thermoacoustic devices. In this study, the performance of jet pumps having 1-16 orifices is characterized experimentally in terms of the time-averaged pressure drop and acoustic power dissipation.
View Article and Find Full Text PDFA computational fluid dynamics model is used to predict the oscillatory flow through tapered cylindrical tube sections (jet pumps). The asymmetric shape of jet pumps results in a time-averaged pressure drop that can be used to suppress Gedeon streaming in closed-loop thermoacoustic devices. However, previous work has shown that flow separation in the diverging flow direction counteracts the time-averaged pressure drop.
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