439 research outputs found
A cycling and education programme for the treatment of hip osteoarthritis: a quality improvement study
AbstractOsteoarthritis of the hip is associated with pain, stiffness and limitations to activities of daily living. The aims of this quality improvement project were to introduce a service developed to promote the self-management of hip osteoarthritis through exercise and education and to assess the impact of the programme on pain, function and quality of life. The service was a six-week cycling and education programme and 119 participants took part. Statistically significant improvements were found for Oxford Hip Scores (Mean (SD) change 4.14, 95%, CI 3.02, 5.25, p < 0.001); Sit-to-stand scores (mean change 3.06, 95%, CI 2.33, 3.79, p < 0.001); EQ5D-5L Utility (mean change 0.06, 95%, CI 0.03, 0.09, p < 0.001); EQ5D VAS (mean change 7.05, 95%, CI 4.72, 9.39, p < 0.001); pain on weight-bearing (WB) (mean change 1.56, 95%, CI 0.77, 2.36, p < 0.001), HOOS function (median change (IQR) 7.35, 1.84 to 19.12, p < 0.001) and TUG test (median change 1.11, 0.31 to 2.43, p < 0.001). Participants reported improvements in pain and function; increased confidence in managing hip pain and an increase in motivation to exercise. These findings were supported by a patient and public involvement forum who suggested extending the programme to eight weeks. These results suggest that the service has potential in the management of hip osteoarthritis
Reynolds-Averaged Turbulence Model Assessment for a Highly Back-Pressured Isolator Flowfield
The use of computational fluid dynamics in scramjet engine component development is widespread in the existing literature. Unfortunately, the quantification of model-form uncertainties is rarely addressed with anything other than sensitivity studies, requiring that the computational results be intimately tied to and calibrated against existing test data. This practice must be replaced with a formal uncertainty quantification process for computational fluid dynamics to play an expanded role in the system design, development, and flight certification process. Due to ground test facility limitations, this expanded role is believed to be a requirement by some in the test and evaluation community if scramjet engines are to be given serious consideration as a viable propulsion device. An effort has been initiated at the NASA Langley Research Center to validate several turbulence closure models used for Reynolds-averaged simulations of scramjet isolator flows. The turbulence models considered were the Menter BSL, Menter SST, Wilcox 1998, Wilcox 2006, and the Gatski-Speziale explicit algebraic Reynolds stress models. The simulations were carried out using the VULCAN computational fluid dynamics package developed at the NASA Langley Research Center. A procedure to quantify the numerical errors was developed to account for discretization errors in the validation process. This procedure utilized the grid convergence index defined by Roache as a bounding estimate for the numerical error. The validation data was collected from a mechanically back-pressured constant area (1 2 inch) isolator model with an isolator entrance Mach number of 2.5. As expected, the model-form uncertainty was substantial for the shock-dominated, massively separated flowfield within the isolator as evidenced by a 6 duct height variation in shock train length depending on the turbulence model employed. Generally speaking, the turbulence models that did not include an explicit stress limiter more closely matched the measured surface pressures. This observation is somewhat surprising, given that stress-limiting models have generally been developed to better predict shock-separated flows. All of the models considered also failed to properly predict the shape and extent of the separated flow region caused by the shock boundary layer interactions. However, the best performing models were able to predict the isolator shock train length (an important metric for isolator operability margin) to within 1 isolator duct height
Laser-Induced Thermal Acoustics Theory and Expected Experimental Errors when Applied to a Scramjet Isolator Model
A scramjet isolator model test apparatus is being assembled in the Isolator Dynamics Research Lab (IDRL) at the NASA Langley Research Center in Hampton, Virginia. The test apparatus is designed to support multiple measurement techniques for investigating the flow field in a scramjet isolator model. The test section is 1-inch high by 2-inch wide by 24-inch long and simulates a scramjet isolator with an aspect ratio of two. Unheated, dry air at a constant stagnation pressure and temperature is delivered to the isolator test section through a Mach 2.5 planar nozzle. The isolator test section is mechanically back-pressured to contain the resulting shock train within the 24-inch isolator length and supports temperature, static pressure, and high frequency pressure measurements at the wall. Additionally, nonintrusive methods including laser-induced thermal acoustics (LITA), spontaneous Raman scattering, particle image velocimetry, and schlieren imaging are being incorporated to measure off-wall fluid dynamic, thermodynamic, and transport properties of the flow field. Interchangeable glass and metallic sidewalls and optical access appendages permit making multiple measurements simultaneously. The measurements will be used to calibrate computational fluid dynamics turbulence models and characterize the back-pressured flow of a scramjet isolator. This paper describes the test apparatus, including the optical access appendages; the physics of the LITA method; and estimates of LITA measurement uncertainty for measurements of the speed of sound and temperature
Laser-Induced Thermal Acoustic Measurements in a Highly Back-Pressured Scramjet Isolator Model: A Research Plan
Under the Propulsion Discipline of NASA s Fundamental Aeronautics Program s Hypersonics Project, a test apparatus, for testing a scramjet isolator model, is being constructed at NASA's Langley Research Center. The test apparatus will incorporate a 1-inch by 2-inch by 15-inch-long scramjet isolator model supplied with 2.1 lbm/sec of unheated dry air through a Mach 2.5 converging-diverging nozzle. The planned research will incorporate progressively more challenging measurement techniques to characterize the flow field within the isolator, concluding with the application of the Laser-Induced Thermal Acoustic (LITA) measurement technique. The primary goal of this research is to use the data acquired to validate Computational Fluid Dynamics (CFD) models employed to characterize the complex flow field of a scramjet isolator. This paper describes the test apparatus being constructed, pre-test CFD simulations, and the LITA measurement technique
Enhanced recovery programmes in knee arthroplasty: current concepts
The concept of a multimodal approach to improve the care of surgical patients was first proposed by Kehlet in the 1990s. Measures to optimise the surgical patient, and minimise perioperative stresses, aimed to improve postoperative outcomes. Although originally introduced in colorectal surgery, these ‘enhanced recovery programmes’ have now seen widespread uptake in multiple surgical specialities, including orthopaedics. Patients undergoing knee arthroplasty are well suited to an enhanced recovery approach. These programmes optimise the patient at each stage of the surgical journey, including preoperative optimisation of fitness, perioperative anaesthetic and surgical techniques and finally postoperative rehabilitation and discharge plans. The available evidence supports a number of improvements after programme introduction, including shorter length of stay, morbidity and economics. However, the impact on other outcomes is less clear. One of the issues in the field is a lack of consensus on what interventions an enhanced recovery programme should contain and the specifics of these interventions. As a result, individual units develop their own programmes, making the interpretation and comparison of their impact difficult. This article discusses interventions that could be considered for inclusion in an enhanced recovery programme for knee arthroplasty
Improving patient reported outcomes in total hip replacement: What can we learn from the "best" and the "poorest" performing sites?
Introduction: Oxford Hip Scores (OHS) and Oxford Knee Scores (OKS) are being collected as part of the Patient Reported Outcome Measures (PROMs) evaluation programme on total hip and knee replacement. This study compares the PROMs outcomes from best and poorest performing English hospitals, as defined by NHS England’s data of elective hip and knee surgery. This was to quantify the difference and identify the scope for improvement. Materials and Methods: OHS and OKS were obtained from the Health and Social Care Information Centre for April 2013 to March 2014. Results: Seven sites for OHS and 10 sites for OKS were above the upper 95% control limit. Fourteen sites for OHS and 10 sites for OKS were below the lower 95% control limit. Median pre-operative scores were similar between best and poorest performers. Median post-operative scores were 4 points higher in best performers. Top OHS-performers scored better in limping, stairs, work, transport, dressing and shopping. Top OKS-performers scored better in walking, shopping and kneeling. Discussion: Pre-operative scores were similar for the best and poorest performers. The differences between best and poorest performing hospitals for OHS and OKS were below the minimum important difference. There was only moderate consistency for outliers. Results for any single year should be treated with caution. Conclusions: PROMs, one of many key tools in measuring and increasing person-centered healthcare, can be useful as part of an evaluation of practice but do not always reveal the full picture. It is important that balanced measures of quality should be used when benchmarking hospitals
The NASA Langley Isolator Dynamics Research Lab
The Isolator Dynamics Research Lab (IDRL) is under construction at the NASA Langley Research Center in Hampton, Virginia. A unique test apparatus is being fabricated to support both wall and in-stream measurements for investigating the internal flow of a dual-mode scramjet isolator model. The test section is 24 inches long with a 1-inch by 2-inch cross sectional area and is supplied with unheated, dry air through a Mach 2.5 converging-diverging nozzle. The test section is being fabricated with two sets (glass and metallic) of interchangeable sidewalls to support flow visualization and laser-based measurement techniques as well as static pressure, wall temperature, and high frequency pressure measurements. During 2010, a CFD code validation experiment will be conducted in the lab in support of NASA s Fundamental Aerodynamics Program. This paper describes the mechanical design of the Isolator Dynamics Research Lab test apparatus and presents a summary of the measurement techniques planned for investigating the internal flow field of a scramjet isolator model
Using Gait Analysis to Evaluate Hip Replacement Outcomes—Its Current Use, and Proposed Future Importance: A Narrative Review
Total hip replacement (THR) is one of the most common elective orthopaedic operations. However, evidence suggests that despite postoperative pain improvements, aspects of longer-term physical performance, such as walking ability, do not reach the levels expected when compared to the general population. Walking is best assessed by using gait analysis. This review aims to explain the concept of gait analysis, its use to evaluate THR outcomes, and its proposed future importance when evaluating new technologies proposed to improve functional recovery in individuals undergoing THR surgery. Furthermore, this review discusses the advantages and challenges of gait analysis in THR patients and provides recommendations for future work
Association of Blood MicroRNA Expression and Polymorphisms with Cognitive and Biomarker Changes in Older Adults
BackgroundIdentifying individuals before the onset of overt symptoms is key in the prevention of Alzheimer's disease (AD).ObjkectivesInvestigate the use of miRNA as early blood-biomarker of cognitive decline in older adults.DesignCross-sectional.SettingTwo observational cohorts (CHARIOT-PRO, Alzheimer's Disease Neuroimaging Initiative (ADNI)).Participants830 individuals without overt clinical symptoms from CHARIOT-PRO and 812 individuals from ADNI.MeasurementsqPCR analysis of a prioritised set of 38 miRNAs in the blood of individuals from CHARIOT-PRO, followed by a brain-specific functional enrichment analysis for the significant miRNAs. In ADNI, genetic association analysis for polymorphisms within the significant miRNAs' genes and CSF levels of phosphorylated-tau, total-tau, amyloid-& beta;42, soluble-TREM2 and BACE1 activity using whole genome sequencing data. Post-hoc analysis using multi-omics datasets.ResultsSix miRNAs (hsa-miR-128-3p, hsa-miR-144-5p, hsa-miR-146a-5p, hsa-miR-26a-5p, hsa-miR-29c-3p and hsa-miR-363-3p) were downregulated in the blood of individuals with low cognitive performance on the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). The pathway enrichment analysis indicated involvement of apoptosis and inflammation, relevant in early AD stages. Polymorphisms within genes encoding for hsa-miR-29c-3p and hsa-miR-146a-5p were associated with CSF levels of amyloid-& beta;42, soluble-TREM2 and BACE1 activity, and 21 variants were eQTL for hippocampal MIR29C expression.Conclusionssix miRNAs may serve as potential blood biomarker of subclinical cognitive deficits in AD. Polymorphisms within these miRNAs suggest a possible interplay between the amyloid cascade and microglial activation at preclinical stages of AD
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