Ceramic applications in turbine engines

The design and testing of gas turbine engines employing ceramic components is discussed. Thermal shock and vibration test results as well as spin tests of various engine components are discussed

Ceramic applications in turbine engines

Ceramic material characterization and testing of ceramic nozzle vanes, turbine tip shrouds, and regenerators disks at 36 C above the baseline engine TIT and the design, analysis, fabrication and development activities are described. The design of ceramic components for the next generation engine to be operated at 2070 F was completed. Coupons simulating the critical 2070 F rotor blade was hot spin tested for failure with sufficient margin to quality sintered silicon nitride and sintered silicon carbide, validating both the attachment design and finite element strength. Progress made in increasing strength, minimizing variability, and developing nondestructive evaluation techniques is reported

Immune compromise in HIV-1/HTLV-1 coinfection with paradoxical resolution of CD4 lymphocytosis during antiretroviral therapy: a case report

Human immunodeficiency virus type-1 (HIV-1) and human T lymphotropic virus type-1 (HTLV-1) infections have complex effects on adaptive immunity, with specific tropism for, but contrasting effects on, CD4 T lymphocytes: depletion with HIV-1, proliferation with HTLV-1. Impaired T lymphocyte function occurs early in HIV-1 infection but opportunistic infections (OIs) rarely occur in the absence of CD4 lymphopenia. In the unusual case where a HIV-1 infected individual with a high CD4 count presents with recurrent OIs, a clinician is faced with the possibility of a second underlying comorbidity. We present a case of pseudo-adult T cell leukemia/lymphoma (ATLL) in HIV-1/HTLV-1 coinfection where the individual fulfilled Shimoyama criteria for chronic ATLL and had pulmonary Mycobacterium kansasii, despite a high CD4 lymphocyte count. However, there was no evidence of clonal T-cell proliferation by T-cell receptor gene rearrangement studies nor of monoclonal HTLV-1 integration by high-throughput sequencing. Mutually beneficial interplay between HIV-1 and HTLV-1, maintaining high level HIV-1 and HTLV-1 viremia and proliferation of poorly functional CD4 cells despite chronicity of infection is a postulated mechanism. Despite good microbiological response to antimycobacterial therapy, the patient remained systemically unwell with refractory anemia. Subsequent initiation of combined antiretroviral therapy led to paradoxical resolution of CD4 T lymphocytosis as well as HIV-1 viral suppression and decreased HTLV-1 proviral load. This is proposed to be the result of attenuation of immune activation post-HIV virological control. This case illustrates the importance of screening for HTLV-1 in HIV-1 patients with appropriate clinical presentation and epidemiological risk factors and explores mechanisms for the complex interactions on HIV-1/HTLV-1 adaptive immunity

Performance enhancement in the measurement of 5 endogenous steroids by LC-MS/MS combined with differential ion mobility spectrometry

pre-printBackground: Challenges for steroid analysis by LC-MS/MS include low ionization efficiency, endogenous isobars with similar fragmentation patterns and chromatographic retention. Differential ion mobility spectrometry (DMS) provides an additional degree of separation prior to MS/MS detection, and shows promise in improving specificity of analysis. We developed a sensitive and specific method for measurement of corticosterone, 11-deoxycortisol, 11-deoxycorticosterone, 17-hydroxyprogesterone and progesterone in human serum and plasma using an ABSciex 5500 mass spectrometer equipped with a differential ion mobility interface. Methods: 250 μL aliquots of serum were spiked with deuterated internal standards and extracted with MTBE. The samples were analyzed using positivemode electrospray LC-DMS-MS/MS. Themethod was validated and compared with immunoassays and LC-MS/MS methods of reference laboratories. Results: Inter and intra assay imprecision was b10%. Limits of quantification and detection in nmol/L were 0.18, 0.09 for corticosterone and 17-hydroxyprogesterone, 0.30, 0.16 for 11-deoxycortisol, 0.12, 0.06 for progesterone and 0.06, 0.03 for 11-deoxycorticosterone. Comparison for progesterone and 17-hydroxyprogesterone with immunoassay showed slopes of 0.97 and 1.0, intercepts of 0.16 and 0.10 and coefficients of determination (r2) of 0.92 and 0.97, respectively. Progesterone by immunoassay showed positive bias in samples measuring b3.18 nmol/L. Reference intervals for progesterone and 11-deoxycorticosterone in post-menopausal women were found to be b2.88 and b0.28 nmol/L respectively. Conclusions: We developed and validated an LC-DMS-MS/MS method for analysis of five endogenous steroids suitable for routine measurements in clinical diagnostic laboratories. Specificity gained with DMS allows reducing the complexity of sample preparation, decreasing LC run times and increasing speed of the analysis

Satellite inferred surface albedo over northwestern Africa

November 1976.Includes bibliographical references (pages 55-56).Sponsored by the Global Atmospheric Research Program, National Science Foundation and the GATE Project Office, NOAA OCD-74-21678.Sponsored by the Global Atmospheric Research Program, National Science Foundation and the GATE Project Office, NOAA OCD-72-01681 A03

Exploring the relationship between geriatric patients and their carers through portraiture: giving, receiving, observing & witnessing care (GROWing Care)

The process of creating a portrait relies on a series of intimate interactions. Portraits, even those that depict a single individual, are a visual testament to a relationship. Portrait sitters are required to engage with artists in the creation of their personal visual narrative. As viewers of a portrait, we are invited to actively participate in other’s stories, to observe, to question, even stare. This process is integral to the portraits evolving meaning. Giving, receiving, observing & witnessing care (GROWing Care), the case study presented in this manuscript, draws on these multiple exchanges to explore the experience of dementia and portraiture among older adults and their partners in care as they work with artist/researcher Mark Gilbert, and geriatrician, Kenneth Rockwood

The Analysis of Protein-Bound Thiocyanate in Plasma of Smokers and Non-Smokers as a Marker of Cyanide Exposure

When cyanide is introduced into the body, it quickly transforms through a variety of chemical reactions, normally involving sulfur donors, to form more stable chemical species. Depending on the nature of the sulfur donor, cyanide may be transformed into free thiocyanate, the major metabolite of cyanide transformation, 2-amino-2-thiazoline-4-carboxylic acid or protein-bound thiocyanate (PB-SCN) adducts. Because protein adducts are generally stable in biological systems, it has been suggested that PB-SCN may have distinct advantages as a marker of cyanide exposure. In this study, plasma was analyzed from 25 smokers (chronic low-level cyanide exposure group) and 25 non-smokers for PB-SCN. The amount of PB-SCN found in the plasma of smokers, 1.35 µM, was significantly elevated (p \u3c 0.0001) when compared to non-smokers, 0.66 µM. Differences in sub-groups of smokers and non-smokers were also evaluated. The results of this study indicate the effectiveness of analyzing PB-SCN in determining instances of chronic cyanide exposure with possible extension to confirmation of acute cyanide exposure

Quantification of α-ketoglutarate cyanohydrin in Swine Plasma by Ultra-high Performance Liquid Chromatography Tandem Mass Spectrometry

Determination of exposure to cyanide can be accomplished by direct cyanide analysis or indirectly by analysis of cyanide detoxification products, such as thiocyanate and 2-amino-2-thiazoline-4-carboxylic acid. A potentially important marker and detoxification product of cyanide exposure, α-ketoglutarate cyanohydrin (α-KgCN), is produced by the reaction of cyanide and α-ketoglutarate. Therefore, an ultra high-performance liquid chromatography tandem mass spectrometry method to determine α-KgCN in plasma was developed. Swine plasma was spiked with α-KgCN and α-KgCN-d4 (internal standard) and proteins were precipitated with 1% formic acid in acetonitrile. After centrifugation, the supernatant was dried, reconstituted, separated by reversed phase high performance liquid chromatography and analyzed by tandem mass spectrometry. The method produced a dynamic range of 0.3–50 μM and a detection limit of 200 nM for α-KgCN. Furthermore, the method produced a %RSD of less than 13% for all intra- and inter-assay analyses. The stability of α-KgCN was poor for most storage conditions tested, except for −80 °C, which produced stable concentrations of α-KgCN for the 30 days tested. The validated method was tested by analysis of α-KgCN in the plasma of cyanide-exposed swine. α-KgCN was not detected pre-exposure, but was detected in all post-exposure plasma samples tested. To our knowledge, this method is the first reported analytical method for detecting α-KgCN in any matrix

A standard procedure for creating a frailty index

<p>Abstract</p> <p>Background</p> <p>Frailty can be measured in relation to the accumulation of deficits using a frailty index. A frailty index can be developed from most ageing databases. Our objective is to systematically describe a standard procedure for constructing a frailty index.</p> <p>Methods</p> <p>This is a secondary analysis of the Yale Precipitating Events Project cohort study, based in New Haven CT. Non-disabled people aged 70 years or older (n = 754) were enrolled and re-contacted every 18 months. The database includes variables on function, cognition, co-morbidity, health attitudes and practices and physical performance measures. Data came from the baseline cohort and those available at the first 18-month follow-up assessment.</p> <p>Results</p> <p>Procedures for selecting health variables as candidate deficits were applied to yield 40 deficits. Recoding procedures were applied for categorical, ordinal and interval variables such that they could be mapped to the interval 0–1, where 0 = absence of a deficit, and 1= full expression of the deficit. These individual deficit scores were combined in an index, where 0= no deficit present, and 1= all 40 deficits present. The values of the index were well fit by a gamma distribution. Between the baseline and follow-up cohorts, the age-related slope of deficit accumulation increased from 0.020 (95% confidence interval, 0.014–0.026) to 0.026 (0.020–0.032). The 99% limit to deficit accumulation was 0.6 in the baseline cohort and 0.7 in the follow-up cohort. Multivariate Cox analysis showed the frailty index, age and sex to be significant predictors of mortality.</p> <p>Conclusion</p> <p>A systematic process for creating a frailty index, which relates deficit accumulation to the individual risk of death, showed reproducible properties in the Yale Precipitating Events Project cohort study. This method of quantifying frailty can aid our understanding of frailty-related health characteristics in older adults.</p