1,126 research outputs found

    Testing alternative fuels, solar-thermal systems

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    The Terrestrial Energy Systems Technical Committee works to advance the application of engineering sciences and systems engineering to the production, storage, distribution and conservation of energy for terrestrial uses

    Vibration Monitoring of Gas Turbine Engines: Machine-Learning Approaches and Their Challenges

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    In this study, condition monitoring strategies are examined for gas turbine engines using vibration data. The focus is on data-driven approaches, for this reason a novelty detection framework is considered for the development of reliable data-driven models that can describe the underlying relationships of the processes taking place during an engine’s operation. From a data analysis perspective, the high dimensionality of features extracted and the data complexity are two problems that need to be dealt with throughout analyses of this type. The latter refers to the fact that the healthy engine state data can be non-stationary. To address this, the implementation of the wavelet transform is examined to get a set of features from vibration signals that describe the non-stationary parts. The problem of high dimensionality of the features is addressed by “compressing” them using the kernel principal component analysis so that more meaningful, lowerdimensional features can be used to train the pattern recognition algorithms. For feature discrimination, a novelty detection scheme that is based on the one-class support vector machine (OCSVM) algorithm is chosen for investigation. The main advantage, when compared to other pattern recognition algorithms, is that the learning problem is being cast as a quadratic program. The developed condition monitoring strategy can be applied for detecting excessive vibration levels that can lead to engine component failure. Here, we demonstrate its performance on vibration data from an experimental gas turbine engine operating on different conditions. Engine vibration data that are designated as belonging to the engine’s “normal” condition correspond to fuels and airto-fuel ratio combinations, in which the engine experienced low levels of vibration. Results demonstrate that such novelty detection schemes can achieve a satisfactory validation accuracy through appropriate selection of two parameters of the OCSVM, the kernel width γ and optimization penalty parameter ν. This selection was made by searching along a fixed grid space of values and choosing the combination that provided the highest cross-validation accuracy. Nevertheless, there exist challenges that are discussed along with suggestions for future work that can be used to enhance similar novelty detection schemes

    Chlorotellurium Compounds of Aryl Ethers

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    Evaluation of granisetron as an antiemetic in patients undergoing abdominal hysterectomy under spinal anaesthesia

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    Background: PONV most common complications related to surgery and anaesthesia despite major advances in spinal, epidural and combined spinal-epidural anesthesia techniques IONV are still present in a significant number of patients. Ondansetron, used for controlling PONV induced by chemotherapy or radiation. Recently 5HT3 receptor antagonist granisetron has more potent, selective and longer acting activity than ondansetron. Granisetron is more active for control of PONV in cisplatin induced vomiting than ondansetron. It also reduces PONV in strabismus repair, tonsillectomy, and general surgeries, it has less side effects as compared to ondansetron. Objective of the study was to study efficacy and safety of granisetron and compare it with ondansetron for prevention of IONV and PONV.Methods: 80 ASA grade I and II women undergoing abdominal hysterectomy under spinal anaesthesia were studied. Patients in group A received injection granisetron 2 mg and group B injection ondansetron 4 mg,10 minutes prior to induction of spinal anaesthesia. Main outcome measures were occurrence of nausea, retching or vomiting in intraoperative and postoperative period at 6, 12, 18 and 24 hours’ post-surgery. The response of patient to therapy and side effects were evaluated in both groups. The results were analyzed by ‘z’ test (p<0.5) considered significant.Results: Demographic characteristics of both groups were comparable patients in granisetron (80%) had more complete response as compared to ondansetron (47.5%). Adverse effects were lower in granisetron group.Conclusions: Granisetron 2 Mg has better efficacy and safety profile than ondansetron 4 Mg

    Misuse of prescription analgesics and predictors of analgesic misuse among urban young adults of Sikkim, India

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    Background: Non-steroid anti-inflammatory drugs (NSAIDs) are the most widely used analgesics and are available without prescription. NSAIDs can be acquired outside of pharmacies, the increase in NSAID consumption and the decrease in professional counseling (by physicians and pharmacists) may pose a serious risk for a substantial increase in adverse effect occurrences. Literature documents several factors affecting the possibility of analgesic misuse such as health status, the frequency and the manner of using analgesics, education and literacy skills (knowledge of safe usage, dosing, combining with other drugs etc.).Aim: The aim of this study was to recognize and describe the important predictive factors of the misuse of prescription analgesics among urban young adults of either sex in Sikkim, India. Methods: A pre devised validated case record form was administered to n=700 subjects. Data was statistically analyzed using Statistical Package of Social Sciences software. Results: Statistically significant results were obtained for pain in the past 30 days (χ2 = 23.282, df=1, P 0.001), source of income (χ2 = 7.326, df=2, P=0.026), smoking in the past 30 days (χ2 = 14.430, df=2, P=0.001), body mass index (χ2 = 140.224, df=2, P 0.001) and depression (χ2 = 13.811, df=2, P=0.001).Conclusion: Several socio-demographic and lifestyle factors along with smoking in the past one month were associated with a continuous regular analgesic misuse of method was carried out utilizing ICH-guidelines. The described HPLC method method was successfully for the analysis of pharmaceutical formulations containing dosage form

    Potential Influence of Advance Care Planning and Palliative Care Consultation on ICU Costs for Patients With Chronic and Serious Illness.

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    OBJECTIVES: To estimate the potential ICU-related cost savings if in-hospital advance care planning and ICU-based palliative care consultation became standard of care for patients with chronic and serious illness. DESIGN AND SETTING: Decision analysis using literature estimates and inpatient administrative data from Premier. PATIENTS: Patients with chronic, life-limiting illness admitted to a hospital within the Premier network. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Using Premier data (2008-2012), ICU resource utilization and costs were tracked over a 1-year time horizon for 2,097,563 patients with chronic life-limiting illness. Using a Markov microsimulation model, we explored the potential cost savings from the hospital system perspective under a variety of scenarios by varying the interventions\u27 efficacies and availabilities. Of 2,097,563 patients, 657,825 (31%) used the ICU during the 1-year time horizon; mean ICU spending per patient was 11.3k (SD, 17.6k). In the base-case analysis, if in-hospital advance care planning and ICU-based palliative care consultation were systematically provided, we estimated a mean reduction in ICU costs of 2.8k (SD, 14.5k) per patient and an ICU cost saving of 25%. Among the simulated patients who used the ICU, the receipt of both interventions could have resulted in ICU cost savings of 1.9 billion, representing a 6% reduction in total hospital costs for these patients. CONCLUSIONS: In-hospital advance care planning and palliative care consultation have the potential to result in significant cost savings. Studies are needed to confirm these findings, but our results provide guidance for hospitals and policymakers

    Medical Student Milestones in Emergency Medicine

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    Objectives Medical education is a continuum from medical school through residency to unsupervised clinical practice. There has been a movement toward competency‐based medical education prompted by the Accreditation Council for Graduate Medical Education ( ACGME ) using milestones to assess competence. While implementation of milestones for residents sets specific standards for transition to internship, there exists a need for the development of competency‐based instruments to assess medical students as they progress toward internship. The objective of this study was to develop competency‐based milestones for fourth‐year medical students completing their emergency medicine ( EM ) clerkships (regardless of whether the students were planning on entering EM ) using a rigorous method to attain validity evidence. Methods A literature review was performed to develop a list of potential milestones. An expert panel, which included a medical student and 23 faculty members (four program directors, 16 clerkship directors, and five assistant deans) from 19 different institutions, came to consensus on these milestones through two rounds of a modified Delphi protocol. The Delphi technique builds content validity and is an accepted method to develop consensus by eliciting expert opinions through multiple rounds of questionnaires. Results Of the initial 39 milestones, 12 were removed at the end of round 1 due to low agreement on importance of the milestone or because of redundancy with other milestones. An additional 12 milestones were revised to improve clarity or eliminate redundancy, and one was added based on expert panelists' suggestions. Of the 28 milestones moving to round 2, consensus with a high level of agreement was achieved for 24. These were mapped to the ACGME EM residency milestone competency domains, as well as the Association of American Medical Colleges ( AAMC ) core entrustable professional activities for entering residency to improve content validity. Conclusions This study found consensus support by experts for a list of 24 milestones relevant to the assessment of fourth‐year medical student performance by the completion of their EM clerkships. The findings are useful for development of a valid method for assessing medical student performance as students approach residency. Resumen Objetivos La formación médica es un continuo que va desde la universidad, pasando por la residencia, hasta la práctica clínica no supervisada. Ha habido un movimiento hacia la formación médica basada en la adquisición de competencias promovido por el Accreditation Council for Graduate Medical Education ( ACGME ) mediante los hitos para evaluar la competencia. Mientras la implementación de los hitos para los residentes establece normas específicas para la transición a residente, existe necesidad de desarrollar instrumentos basados en la competencia para evaluar a los estudiantes de medicina según progresan hacia la residencia. El objetivo de este estudio fue desarrollar los hitos basados ​​en competencias para los estudiantes de medicina de cuarto año al completar sus prácticas clínicas en Medicina de Urgencias y Emergencias ( MUE ) (indistintamente si el estudiante planeaba acceder a la MUE ) utilizando un método riguroso para lograr evidencia válida. Metodología Se realizó una revisión de la literatura para desarrollar una lista de hitos potenciales. Un panel de expertos, que incluyó 23 profesores de la facultad cuyas responsabilidades eran directores de programa (4), directores de prácticas clínicas (16), vicedecanos (5) y un estudiante de medicina de 19 instituciones diferentes, llegaron a un consenso sobre estos hitos a través de 2 rondas del protocolo de Delphi modificado. La técnica Delphi construye un contenido válido y es un método aceptado para desarrollar un consenso mediante la obtención de opiniones de expertos a través de múltiples rondas de preguntas. Resultados De los 39 hitos iniciales, se eliminaron 12 al final de la primera ronda debido al bajo acuerdo sobre la importancia del hito o debido a su redundancia con otros hitos. Se revisaron 12 hitos adicionales para mejorar la claridad o eliminar la redundancia, y se añadió uno basado en las sugerencias del panel de expertos. De los 28 hitos que llegaron a la segunda ronda, se alcanzó un consenso con un alto nivel de acuerdo para 24 de los hitos. Estos hitos se esquematizaron a los dominios de competencia de los hitos de la residencia de MUE del ACGME , así como a las actividades profesionales recomendadas para acceder a la residencia de la Association of American Medical Colleges ( AAMC ) para mejorar la validez de contenido. Conclusiones Este estudio llegó a un consenso apoyado por expertos para una lista de 24 hitos relevantes para evaluar el rendimiento de los estudiantes de medicina de cuarto año al finalizar su práctica clínica en MUE . Los hallazgos son útiles para el desarrollo de un método válido para evaluar el rendimiento de los estudiantes de medicina a medida que éstos se acercan a la residencia.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/108261/1/acem12443-sup-0002-DataSupplementS2.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/108261/2/acem12443.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/108261/3/acem12443-sup-0001-DataSupplementS1.pd

    Evaluating the Economic Impact of Palliative and End-of-Life Care Interventions on Intensive Care Unit Utilization and Costs from the Hospital and Healthcare System Perspective.

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    Purpose of report: Understanding the impact of palliative care interventions on intensive care unit (ICU) costs and utilization is critical for demonstrating the value of palliative care. Performing these economic assessments, however, can be challenging. The purpose of this special report is to highlight and discuss important considerations when assessing ICU utilization and costs from the hospital perspective, with the goal of providing recommendations on methods to consider for future analyses. FINDINGS: ICU length of stay (LOS) and associated costs of care are common and important outcome measures, but must be analyzed properly to yield valid conclusions. There is significant variation in costs by day of stay in the ICU with only modest differences between an ICU day at the end of a stay and the first day on the acute care floor; this variation must be appropriately accounted for analytically. Furthermore, reporting direct variable costs, in addition to total ICU costs, is needed to understand short-term and long-term impact of a reduction in LOS. Importantly, incentives for the hospital to realize savings vary depending on reimbursement policies. SUMMARY: ICU utilization and costs are common outcomes in studies evaluating palliative care interventions. Accurate estimation and interpretation are key to understanding the economic implications of palliative care interventions

    Patterns of Cost for Patients Dying in the Intensive Care Unit and Implications for Cost Savings of Palliative Care Interventions.

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    BACKGROUND: Terminal intensive care unit (ICU) stays represent an important target to increase value of care. OBJECTIVE: To characterize patterns of daily costs of ICU care at the end of life and, based on these patterns, examine the role for palliative care interventions in enhancing value. DESIGN: Secondary analysis of an intervention study to improve quality of care for critically ill patients. SETTING/PATIENTS: 572 patients who died in the ICU between 2003 and 2005 at a Level-1 trauma center. METHODS: Data were linked with hospital financial records. Costs were categorized into direct fixed, direct variable, and indirect costs. Patterns of daily costs were explored using generalized estimating equations stratified by length of stay, cause of death, ICU type, and insurance status. Estimates from the literature of effects of palliative care interventions on ICU utilization were used to simulate potential cost savings under different time horizons and reimbursement models. MAIN RESULTS: Mean cost for a terminal ICU stay was 39.3K ± 45.1K. Direct fixed costs represented 45% of total hospital costs, direct variable costs 20%, and indirect costs 34%. Day of admission was most expensive (mean 9.6K ± 7.6K); average cost for subsequent days was 4.8K ± 3.4K and stable over time and patient characteristics. CONCLUSIONS: Terminal ICU stays display consistent cost patterns across patient characteristics. Savings can be realized with interventions that align care with patient preferences, helping to prevent unwanted ICU utilization at end of life. Cost modeling suggests that implications vary depending on time horizon and reimbursement models
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