149 research outputs found

    70 Years of Aeropropulsion Research at NASA Glenn Research Center

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    This paper presents a brief overview of air-breathing propulsion research conducted at the NASA Glenn Research Center (GRC) over the past 70 years. It includes a historical perspective of the center and its various stages of propulsion research in response to the countrys different periods of crises and growth opportunities. GRCs research and technology development covered a broad spectrum, from a short-term focus on improving the energy efficiency of aircraft engines to advancing the frontier technologies of high-speed aviation in the supersonic and hypersonic speed regimes. This paper highlights major research programs, showing their impact on industry and aircraft propulsion, and briefly discusses current research programs and future aeropropulsion technology trends in related area

    An Overview of Low-Emission Combustion Research at NASA Glenn

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    An overview of research efforts at NASA Glenn Research Center (GRC) in low-emission combustion technology that have made a significant impact on the nitrogen oxides (NOx) emission reduction in aircraft propulsion is presented. The technology advancements and their impact on aircraft emissions are discussed in the context of NASA's Aeronautics Research Mission Directorate (ARMD) high-level goals in fuel burn, noise and emission reductions. The highlights of the research presented here show how the past and current efforts laid the foundation for the engines that are flying today as well as how the continued technology advancements will significantly influence the next generation of aviation propulsion system designs

    The prevalence of platelet activating factor acetylhydrolase single nucleotide polymorphisms in relationship to necrotizing enterocolitis in Northwest Louisiana infants

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    PURPOSE: Studies documented that platelet activating factor (PAF) and the enzyme platelet activating factor acetylhydrolase (PAFAH) play a very important role in the pathogenesis of neonatal necrotizing enterocolitis (NEC). In this retrospective, case-controlled pilot study, the authors investigated the prevalence of single nucleotide polymorphisms (Ile198Thr and Ala379Val) of the PAFAH gene. SUBJECTS AND METHODS: We screened 570 blood samples from both Caucasian and African-American preterm infants in the Northwest Louisiana population for the above mentioned PAFAH gene polymorphisms. Out of 570 infants, 36 had stage I or II NEC based on diagnostic coding, the International Classification of Diseases, 9th revision, Clinical Modification, 2009 (ICD-9-CM). The remaining infants without an ICD-9-CM diagnosis of NEC were recruited as control population. The DNA was isolated and restriction fragment length polymorphism microplate polymerase chain reaction assay was performed. RESULTS: Variants of the PAFAH gene polymorphism (Ile198Thr and Ala379Val) frequencies were not significantly different between the infants with NEC and the control group (P value of 0.26 by either multiple logistic regression analysis or the Cochran-Mantel-Haenszel test). CONCLUSIONS: This is the first study of its kind in exploring the relationship between NEC and single nucleotide polymorphisms in the coding genes of the enzyme PAFAH. Our preliminary data demonstrated that adjusted for the effect of race, PAFAH polymorphisms (Ile198Thr and Ala379Val) have no significant effect on NEC

    Mechanical ventilation interacts with endotoxemia to induce extrapulmonary organ dysfunction

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    INTRODUCTION: Multiple organ dysfunction syndrome (MODS) is a common complication of sepsis in mechanically ventilated patients with acute respiratory distress syndrome, but the links between mechanical ventilation and MODS are unclear. Our goal was to determine whether a minimally injurious mechanical ventilation strategy synergizes with low-dose endotoxemia to induce the activation of pro-inflammatory pathways in the lungs and in the systemic circulation, resulting in distal organ dysfunction and/or injury. METHODS: We administered intraperitoneal Escherichia coli lipopolysaccharide (LPS; 1 μg/g) to C57BL/6 mice, and 14 hours later subjected the mice to 6 hours of mechanical ventilation with tidal volumes of 10 ml/kg (LPS + MV). Comparison groups received ventilation but no LPS (MV), LPS but no ventilation (LPS), or neither LPS nor ventilation (phosphate-buffered saline; PBS). RESULTS: Myeloperoxidase activity and the concentrations of the chemokines macrophage inflammatory protein-2 (MIP-2) and KC were significantly increased in the lungs of mice in the LPS + MV group, in comparison with mice in the PBS group. Interestingly, permeability changes across the alveolar epithelium and histological changes suggestive of lung injury were minimal in mice in the LPS + MV group. However, despite the minimal lung injury, the combination of mechanical ventilation and LPS resulted in chemical and histological evidence of liver and kidney injury, and this was associated with increases in the plasma concentrations of KC, MIP-2, IL-6, and TNF-α. CONCLUSION: Non-injurious mechanical ventilation strategies interact with endotoxemia in mice to enhance pro-inflammatory mechanisms in the lungs and promote extra-pulmonary end-organ injury, even in the absence of demonstrable acute lung injury

    Exploring unusual metastasis in carcinoma breast: Divulging vulval metastasis

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    Regional lymph nodes, bones, brain, lung, and liver are the most common sites of the breast carcinoma metastases. Nodular or ulcerated lesions over the vulva are ignored for a long time as benign lesions by the patient and there is a lot of hesitance to undergo the examination. Here, we report the case of a 41-year-old female with an isolated, asymptomatic vulval metastasis of Invasive ductal carcinoma of the breast. The purpose of reporting this case is to make the clinicians aware of this rare site of metastasis of breast cancer and the importance of pelvic examination in follow-up patients

    Use of a Community Center Primary Care Clinic and Subsequent Emergency Department Visits among Unhoused Women

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    Funding/Support: Dr Stewart was supported by grants T32AI007044 and K23MH124466 from the National Institutes of Health (NIH), and Dr Stadeli was supported by training grant T32DK070555 from the NIH. The use of REDCap (Research Electronic Data Capture) software (Vanderbilt University) was supported by grants UL1TR002319, KL2TR002317, and TL1TR002318 from the Institute of Translational Health Science and from the National Center for Advancing Translational Sciences/NIH. The Safe. Healthy. Empowered (SHE) Clinic pilot program was supported by grants from Lahai Health for the period of April 1, 2018 through March 31, 2019, and by the City of Seattle Human Services Department. A mobile van owned and operated by Puget Sound Christian Clinic was used in the study.This cohort study evaluates the association between use of a community center primary care clinic and subsequent nonemergent emergency department (ED) visits by unhoused women who exchange sex and inject drugs.Peer reviewe

    Renal transplantation in children managed with lymphocyte depleting agents and low-dose maintenance tacrolimus monotherapy

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    OBJECTIVE. Describe the safety and efficacy of antithymocyte globulin or alemtuzumab preconditioning, steroid avoidance and reduced calcineurin inhibitor (CNI) immunosuppression in 34 children undergoing renal transplantation. METHODS. ATG (n=8) or alemtuzumab (n=26) were infused at the time of transplantation. This was followed by low-dose twice a day tacrolimus monotherapy with consolidation to once daily dosing by 6 months and once every other day dosing by 12 months. Follow-up ranged from 0.5-2.9 years (mean 1.33 years), with a minimum of 6 months. RESULTS. Both ATG and alemtuzumab were well tolerated. Lymphopenia occurred routinely and resolved after 3-6 months. Acute cellular rejection occurred in 9%; it was related to medical nonadherence in two patients and resulted in one graft loss at 1.5 years. Important adverse events included transient neutropenia in 10 children (none with serious infection), and autoimmune hemolytic anemia in two (resolved with a steroid course in both and conversion to sirolimus in one). Estimated glomerular filtration rate (e-GFR) was stable and averaged 88 mL/min/1.73 m at latest follow-up. Fifteen preadolescents had a greater increase in height Z-score at 1 year (1.3 vs. 0.5, P=0.001), and a higher e-GFR (94.8±21 vs. 76.6±20 ml/min/1.73 m, P<0.05), when compared to case-matched historical controls who were weaned off steroids by 6 months after transplantation and received twice daily tacrolimus monotherapy. CONCLUSION. This simple regimen appears safe, has a low risk for acute cellular rejection or other adverse effects, and is associated with excellent growth and renal function. Such a regimen may also improve compliance and limit CNI nephrotoxicity. © 2007 Lippincott Williams & Wilkins, Inc

    Design and baseline characteristics of the finerenone in reducing cardiovascular mortality and morbidity in diabetic kidney disease trial

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    Background: Among people with diabetes, those with kidney disease have exceptionally high rates of cardiovascular (CV) morbidity and mortality and progression of their underlying kidney disease. Finerenone is a novel, nonsteroidal, selective mineralocorticoid receptor antagonist that has shown to reduce albuminuria in type 2 diabetes (T2D) patients with chronic kidney disease (CKD) while revealing only a low risk of hyperkalemia. However, the effect of finerenone on CV and renal outcomes has not yet been investigated in long-term trials. Patients and Methods: The Finerenone in Reducing CV Mortality and Morbidity in Diabetic Kidney Disease (FIGARO-DKD) trial aims to assess the efficacy and safety of finerenone compared to placebo at reducing clinically important CV and renal outcomes in T2D patients with CKD. FIGARO-DKD is a randomized, double-blind, placebo-controlled, parallel-group, event-driven trial running in 47 countries with an expected duration of approximately 6 years. FIGARO-DKD randomized 7,437 patients with an estimated glomerular filtration rate >= 25 mL/min/1.73 m(2) and albuminuria (urinary albumin-to-creatinine ratio >= 30 to <= 5,000 mg/g). The study has at least 90% power to detect a 20% reduction in the risk of the primary outcome (overall two-sided significance level alpha = 0.05), the composite of time to first occurrence of CV death, nonfatal myocardial infarction, nonfatal stroke, or hospitalization for heart failure. Conclusions: FIGARO-DKD will determine whether an optimally treated cohort of T2D patients with CKD at high risk of CV and renal events will experience cardiorenal benefits with the addition of finerenone to their treatment regimen. Trial Registration: EudraCT number: 2015-000950-39; ClinicalTrials.gov identifier: NCT02545049
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