598 research outputs found
Emissions control for ground power gas turbines
The similarities and differences of emissions reduction technology for aircraft and ground power gas turbines is described. The capability of this technology to reduce ground power emissions to meet existing and proposed emissions standards is presented and discussed. Those areas where the developing aircraft gas turbine technology may have direct application to ground power and those areas where the needed technology may be unique to the ground power mission are pointed out. Emissions reduction technology varying from simple combustor modifications to the use of advanced combustor concepts, such as catalysis, is described and discussed
Prestress for maximum strength
The problem of designing prestress to maximize elastic capacity is treated analytically. Our formulation models structures comprised of a one-material elastic continuum, subject to a single deterministic load configuration.The equations needed to predict the optimal prestress design are derived. They are shown to comprise necessary and sufficient conditions for global maximum strength in the unconstrained design problem. The theory is demonstrated on the design of prestress for a thick-walled cylinder.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/33778/1/0000031.pd
Impact of Baseline Magnetic Resonance Imaging on Neurologic, Functional, and Safety Outcomes in Patients With Acute Traumatic Spinal Cord Injury
Study Design: Systematic review. Objective: To perform a systematic review to evaluate the utility of magnetic resonance imaging (MRI) in patients with acute spinal cord injury (SCI). Methods: An electronic search of Medline, EMBASE, the Cochrane Collaboration Library, and Google Scholar was conducted for literature published through May 12, 2015, to answer key questions associated with the use of MRI in patients with acute SCI. Results: The literature search yielded 796 potentially relevant citations, 8 of which were included in this review. One study used MRI in a protocol to decide on early surgical decompression. The MRI-protocol group showed improved outcomes; however, the quality of evidence was deemed very low due to selection bias. Seven studies reported MRI predictors of neurologic or functional outcomes. There was moderate-quality evidence that longer intramedullary hemorrhage (2 studies) and low-quality evidence that smaller spinal canal diameter at the location of maximal spinal cord compression and the presence of cord swelling are associated with poor neurologic recovery. There was moderate-quality evidence that clinical outcomes are not predicted by SCI lesion length and the presence of cord edema. Conclusions: Certain MRI characteristics appear to be predictive of outcomes in acute SCI, including length of intramedullary hemorrhage (moderate-quality evidence), canal diameter at maximal spinal cord compression (low-quality evidence), and spinal cord swelling (low-quality evidence). Other imaging features were either inconsistently (presence of hemorrhage, maximal canal compromise, and edema length) or not associated with outcomes. The paucity of literature highlights the need for well-designed prospective studies. © 2017, © The Author(s) 2017
Cervical spine surgery for tandem spinal stenosis: The impact on low back pain
Objective
Tandem spinal stenosis (TSS) can present similarly to cervical myelopathy, but often has a worse prognosis. Few studies have investigated outcomes and compared treatment approaches for patients with TSS. We sought to determine the impact of cervical spine surgery on cervical and lumbar spine symptoms in patients with symptomatic tandem spinal stenosis.
Patients Methods
84 patients with TSS were identified over 5 years. 48 underwent cervical spine surgery alone, 20 underwent both cervical and lumbar spine surgery, and 16 received conservative treatment alone (conservative cohort). Quality of life (QOL) measures included the Visual Analogue Scale (VAS) for arm, neck, and back pain, and EuroQOL-5 Dimensions (EQ-5D). QOL data were acquired at baseline (pre-operative) and 1 year postoperatively via an institutional prospectively collected database.
Results
Both surgical cohorts showed significant (p < 0.01) pre- to postoperative improvement for VAS neck and arm scores at 1-year post-op and significantly (p < 0.01) greater improvements than the conservative cohort. In addition, the cohort undergoing cervical spine surgery alone experienced significant improvement in the EQ-5D score whereas those undergoing both cervical and lumbar spine surgery did not.
Conclusions
Cervical spine surgery with or without follow-up lumbar spine surgery significantly improves neck pain in patients with TSS. In contrast, cervical spine surgery in these patients does not improve lumbar symptoms. Lumbar surgery also did not improve low back pain or quality of life. Future prospective studies are necessary to examine the impact of lumbar decompression alone on cervical spine symptoms in patients with TSS
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Increasing TRUPACT-II wattage limits: two technical approaches
More than one-third of the drums in DOE`s TRU waste inventory cannot be presently shipped to WIPP in the TRUPACT-11 because they exceed the allowed limit of heat generation by virtue of radioactive decay. This limit was imposed to ensure that the amount of hydrogen generated by radiolysis does not achieve the lower explosive limit of hydrogen in air (5 percent v/v). Los Alamos is working to justify increasing these wattage limits: (1) by demonstrating that the phenomenon of matrix depletion greatly reduces the potential for hydrogen generation and (2) by investigating the use hydrogen getters to actively remove hydrogen from the headspace of the waste drums and/or the TRUPACT-11
Superior Segment Facet Joint Violation During Instrumented Lumbar Fusion is Associated With Higher Reoperation Rates and Diminished Improvement in Quality of Life
Study Design: A retrospective cohort study at a single tertiary care center.
Objective: To determine the impact of superior segment facet joint violation (FJV) during lumbar fusion on reoperation rates and quality of life (QOL).
Summary of Background Data: Although lumbar fusion is an efficacious and durable treatment for numerous spinal pathologies, adjacent segment degeneration remains a serious complication. FJV has been suggested to alter load-bearing capability and potentially contribute to adjacent segment degeneration.
Materials and Methods: Patients who underwent instrumented lumbar fusion surgery between 2009 and 2013 with postoperative computed tomography imaging were included. Patients were placed in the FJV group if either of the superior segment facet joints were compromised by the pedicle screw or rod. Patients with preserved facet joints were placed in the control group. Demographic, perioperative, QOL, and reoperation data were collected. QOL scores including the Pain Disability Questionnaire, Patient Health Questionnaire-9, and EuroQOL 5 Dimensions (EQ-5D) were acquired.
Results: Of 240 patients included, 112 patients were found to have FJV and the remaining 128 patients were placed in the control group. One year following lumbar fusion, QOL outcomes and reoperation rates were similar between the FJV and control groups. At 2-year follow-up, patients in the FJV group were less likely to make a significant improvement in EQ-5D (P=0.041). Also, the reoperation rate in the FJV group was significantly higher than in the control group at 2 years (15.2% vs. 6.3%, respectively; P=0.024) and 3 years (19.6% vs. 9.4%, P=0.023). Multivariable logistic regression showed FJV to be an independent predictor of both (1) failing to make a significant improvement in EQ-5D (P=0.046) and (2) undergoing reoperation at both 2 and 3 years postoperatively (P=0.024 and 0.020, respectively).
Conclusions: FJV was independently associated with a higher reoperation rate and diminished improvement in QOL
BASIS: High-performance bioinformatics platform for processing of large-scale mass spectrometry imaging data in chemically augmented histology
Mass Spectrometry Imaging (MSI) holds significant promise in augmenting digital histopathologic analysis by generating highly robust big data about the metabolic, lipidomic and proteomic molecular content of the samples. In the process, a vast quantity of unrefined data, that can amount to several hundred gigabytes per tissue section, is produced. Managing, analysing and interpreting this data is a significant challenge and represents a major barrier to the translational application of MSI. Existing data analysis solutions for MSI rely on a set of heterogeneous bioinformatics packages that are not scalable for the reproducible processing of large-scale (hundreds to thousands) biological sample sets. Here, we present a computational platform (pyBASIS) capable of optimized and scalable processing of MSI data for improved information recovery and comparative analysis across tissue specimens using machine learning and related pattern recognition approaches. The proposed solution also provides a means of seamlessly integrating experimental laboratory data with downstream bioinformatics interpretation/analyses, resulting in a truly integrated system for translational MSI
Relationship Between Isometric Inter-Limb Asymmetry and Strength of the Lower Extremity in Military Personnel
Positional Differences in Areal Bone Mineral Density and Body Composition in NCAA Division - I Football Athletes
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