191 research outputs found

    Centrifugal Pump Operation, Maintenance, and Reliability

    Get PDF
    Discussion GroupRepair Specs, use, in house repair specs Lube oil storage and usage Mechanical seals and bearings issues Pump monitoring how are we doing this and how do we want to do this Craft training precision maintenance Best practices for pump maintenance; Back pullout vs. pulling entire pump: Open bearing housings vs sealed wet sump Seal plan which was not expected wrong for the application Preventive/predictive technologies Off design operation Mean time between failure (MTBF), other KPIs how do we measure, and how do we use the metrics How to create pump reliability in an unreliable plant Seal-less versus sealed pump reliability, canned motor pumps versus mag drive pump reliability Mechanical Integrity Inspections of VS 6 pumps in hydrocarbon service Seals in light hydrocarbon service operations, risk, leak response, maintenance Pump predictive/preventive maintenance program elements philosophy, frequencies. Measures of effectiveness of preventive and predictive programs for pumps Roles of operations and maintenance/reliability in improvements and data collection Reliability experience with liquid versus non contacting gas seals applications Maintenance philosophy for pumps what constitutes best practices Spare parts OEM versus non-OEM Repairs OEM versus non-OEM service facilities Pump foundation, alignment and pipe strain influence of reliability Impact of corporate purchasing alliances on pump reliability a. Repair facilities alliances b. New equipment purchasing alliances Repair techniques and material improvements Portable and on-line monitoring impact on reliability Wireless monitoring impact on reliability and risk of failure Optimization of thrust bearings configuratio

    Nebivolol, a beta adrenergic receptor antagonist blocks angiotensin II-mediated signaling in heart [abstract]

    Get PDF
    We recently showed that Nebivolol, a [beta]-adrenergic receptor (AR) antagonist attenuates myocardial oxidative stress and promotes insulin metabolic signaling in 9 week old Zucker obese (ZO) insulin resistant rats. Here, we demonstrate that Nebivolol suppresses angiotensin II type I receptor (AT1R)-mediated signaling in ZO hearts as well as in HL-1 cardiomyocytes

    Dysglycemia but not lipids is associated with abnormal urinary albumin excretion in diabetic kidney disease: a report from the Kidney Early Evaluation Program (KEEP)

    Get PDF
    BACKGROUND: The relationship between glycemic control and lipid abnormalities with urinary albumin-creatinine ratio (ACR) in chronic kidney disease (CKD) patients with diabetes mellitus (DM) is unknown. We sought to investigate the association of dyslipidemia and glycemic control with levels of albuminuria in the National Kidney Foundation (NKF) Kidney Early Evaluation Program (KEEP) participants with DM and CKD stage 3 or higher. METHODS: We performed a cross-sectional study of 6639 eligible KEEP patients with DM and CKD Stage 3 to 5 from June 2008 to December 2009. Multivariate logistic regression was used to evaluate the association of lipid parameters (per 10 mg/dl change in serum level) and glycosylated hemoglobin (HbA1c) values with three degrees of albuminuria normo (<30 mg⁄g), micro (30 to 300 mg⁄g) and macro (>300 mg⁄g). RESULTS: 2141 KEEP participants were included. HbA1c levels were strongly associated with micro-albuminuria (compared to normo-albuminuria) and macro-albuminuria (compared to normo-albuminuria and micro-albuminuria). Each 1.0% increase in HbA1c increased the odds of micro-albuminuria by 32% (OR 1.32, 95% CI 1.23-1.42) and the odds of macro-albuminuria (vs. microalbuminuria) by 16% (OR 1.16, 95% CI 1.05-1.28). Only increases in serum HDL were associated with decreased odds of micro-albuminuria; otherwise, the association between other components of the serum lipid profile with urinary ACR did not reach statistical significance. CONCLUSION: In this cross-sectional study of 2141 KEEP participants with DM and CKD stages 3–5, overall glycemic control but not lipids were associated with abnormal urinary albumin excretion, a marker of increased risk for progressive disease

    Mutations in TAC1B: a Novel Genetic Determinant of Clinical Fluconazole Resistance in Candida auris

    Get PDF
    Candida auris is an emerging multidrug-resistant pathogen of global concern, known to be responsible for outbreaks on six continents and to be commonly resistant to antifungals. While the vast majority of clinical C. auris isolates are highly resistant to fluconazole, an essential part of the available antifungal arsenal, very little is known about the mechanisms contributing to resistance. In this work, we show that mutations in the transcription factor TAC1B significantly contribute to clinical fluconazole resistance. These studies demonstrated that mutations in TAC1B can arise rapidly in vitro upon exposure to fluconazole and that a multitude of resistance-associated TAC1B mutations are present among the majority of fluconazole-resistant C. auris isolates from a global collection and appear specific to a subset of lineages or clades. Thus, identification of this novel genetic determinant of resistance significantly adds to the understanding of clinical antifungal resistance in C. auris.Candida auris has emerged as a multidrug-resistant pathogen of great clinical concern. Approximately 90% of clinical C. auris isolates are resistant to fluconazole, the most commonly prescribed antifungal agent, and yet it remains unknown what mechanisms underpin this fluconazole resistance. To identify novel mechanisms contributing to fluconazole resistance in C. auris, fluconazole-susceptible C. auris clinical isolate AR0387 was passaged in media supplemented with fluconazole to generate derivative strains which had acquired increased fluconazole resistance in vitro. Comparative analyses of comprehensive sterol profiles, [3H]fluconazole uptake, sequencing of C. auris genes homologous to genes known to contribute to fluconazole resistance in other species of Candida, and relative expression levels of C. aurisERG11, CDR1, and MDR1 were performed. All fluconazole-evolved derivative strains were found to have acquired mutations in the zinc-cluster transcription factor-encoding gene TAC1B and to show a corresponding increase in CDR1 expression relative to the parental clinical isolate, AR0387. Mutations in TAC1B were also identified in a set of 304 globally distributed C. auris clinical isolates representing each of the four major clades. Introduction of the most common mutation found among fluconazole-resistant clinical isolates of C. auris into fluconazole-susceptible isolate AR0387 was confirmed to increase fluconazole resistance by 8-fold, and the correction of the same mutation in a fluconazole-resistant isolate, AR0390, decreased fluconazole MIC by 16-fold. Taken together, these data demonstrate that C. auris can rapidly acquire resistance to fluconazole in vitro and that mutations in TAC1B significantly contribute to clinical fluconazole resistance

    Centrifugal Pump Operation, Maintenance, and Reliability

    Get PDF
    Discussion GroupRepair Specs, use, in house repair specs Lube oil storage and usage Mechanical seals and bearings issues Pump monitoring how are we doing this and how do we want to do this Craft training precision maintenance Best practices for pump maintenance; Back pullout vs. pulling entire pump: Open bearing housings vs sealed wet sump Seal plan which was not expected wrong for the application Preventive/predictive technologies Off design operation Mean time between failure (MTBF), other KPIs how do we measure, and how do we use the metrics How to create pump reliability in an unreliable plant Seal-less versus sealed pump reliability, canned motor pumps versus mag drive pump reliability Mechanical Integrity Inspections of VS 6 pumps in hydrocarbon service Seals in light hydrocarbon service operations, risk, leak response, maintenance Pump predictive/preventive maintenance program elements philosophy, frequencies. Measures of effectiveness of preventive and predictive programs for pumps Roles of operations and maintenance/reliability in improvements and data collection Reliability experience with liquid versus non contacting gas seals applications Maintenance philosophy for pumps what constitutes best practices Spare parts OEM versus non-OEM Repairs OEM versus non-OEM service facilities Pump foundation, alignment and pipe strain influence of reliability Impact of corporate purchasing alliances on pump reliability a. Repair facilities alliances b. New equipment purchasing alliances Repair techniques and material improvements Portable and on-line monitoring impact on reliability Wireless monitoring impact on reliability and risk of failure Optimization of thrust bearings configuratio

    Mineralocorticoid receptor antagonism attenuates vascular apoptosis and injury via rescuing protein kinase B activation

    Get PDF
    This article may also be found at the publisher's website at http://hyper.ahajournals.org/cgi/content/abstract/53/2/158?maxtoshow=&HITS=10&hits=10&RESULTFORMAT=&fulltext=habibi&searchid=1&FIRSTINDEX=0&resourcetype=HWCITEmerging evidence indicates that mineralocorticoid receptor (MR) blockade reduces the risk of cardiovascular events beyond those predicted by its blood pressure-lowering actions; however, the underlying mechanisms remain unclear. To investigate whether protection elicited by MR blockade is through attenuation of vascular apoptosis and injury, independently of blood pressure lowering, we administered a low dose of the MR antagonist spironolactone or vehicle for 21 days to hypertensive transgenic Ren2 rats with elevated plasma aldosterone levels. Although Ren2 rats developed higher systolic blood pressures compared with Sprague-Dawley littermates, low-dose spironolactone treatment did not reduce systolic blood pressure compared with untreated Ren2 rats. Ren2 rats exhibited vascular injury as evidenced by increased apoptosis, hemidesmosome-like structure loss, mitochondrial abnormalities, and lipid accumulation compared with Sprague-Dawley rats, and these abnormalities were attenuated by MR antagonism. Protein kinase B activation is critical to vascular homeostasis via regulation of cell survival and expression of apoptotic genes. Protein kinase B serine473 phosphorylation was impaired in Ren2 aortas and restored with MR antagonism. In vivo MR antagonist treatment promoted antiapoptotic effects by increasing phosphorylation of BAD serine136 and expression of Bcl-2 and Bcl-xL, decreasing cytochrome c release and BAD expression, and suppressing caspase-3 activation. Furthermore, MR antagonism substantially reduced the elevated NADPH oxidase activity and lipid peroxidation, expression of angiotensin II, angiotensin type 1 receptor, and MR in Ren2 vasculature. These results demonstrate that MR antagonism protects the vasculature from aldosterone-induced vascular apoptosis and structural injury via rescuing protein kinase B activation, independent of blood pressure effects
    corecore