CVD aluminiding process for producing a modified platinum aluminide bond coat for improved high temperature performance

A method of depositing by chemical vapor deposition a modified platinum aluminide diffusion coating onto a superalloy substrate comprising the steps of applying a layer of a platinum group metal to the superalloy substrate; passing an externally generated aluminum halide gas through an internal gas generator which is integral with a retort, the internal gas generator generating a modified halide gas; and co-depositing aluminum and modifier onto the superalloy substrate. In one form, the modified halide gas is hafnium chloride and the modifier is hafnium with the modified platinum aluminum bond coat comprising a single phase additive layer of platinum aluminide with at least about 0.5 percent hafnium by weight percent and about 1 to about 15 weight percent of hafnium in the boundary between a diffusion layer and the additive layer. The bond coat produced by this method is also claimed

Application of a Third Order Upwind Scheme to Viscous Flow over Clean and Iced Wings

A 3-D compressible Navier-Stokes solver has been developed and applied to 3-D viscous flow over clean and iced wings. This method uses a third order accurate finite volume scheme with flux difference splitting to model the inviscid fluxes, and second order accurate symmetric differences to model the viscous terms. The effects of turbulence are modeled using a Kappa-epsilon model. In the vicinity of the sold walls the kappa and epsilon values are modeled using Gorski's algebraic model. Sampling results are presented for surface pressure distributions, for untapered swept clean and iced wings made of NACA 0012 airfoil sections. The leading edge of these sections is modified using a simulated ice shape. Comparisons with experimental data are given

Screening Mammography for Reducing Breast Cancer Mortality

Screening mammography reduces breast cancer mortality in women 40 to 49 years of age who have an average risk of breast cancer. (Strength of Recommendation: A, based on eight randomized controlled trials [RCTs].) The relative risk reduction in this age group is 15 percent, similar to that of women 50 years and older (14 percent). To prevent one breast cancer death, 1,904 women 40 to 49 years of age must be screened annually for 10 years, compared with 1,339 women 50 to 59 years of age. Although both age groups appear to have a similar relative risk reduction from routine screening, women 40 to 49 years of age have a smaller absolute risk reduction and may experience greater harms from screening compared with older women. These potential harms include false-positive results, diagnosis and treatment for cancer that would not have become clinically evident during the woman's lifetime, false-negative results (i.e., false reassurance), radiation exposure, biopsies, and anxiety

Everolimus-eluting stents or bypass surgery for multivessel coronary disease

Copyright © 2015 Massachusetts Medical Society. BACKGROUND: Results of trials and registry studies have shown lower long-term mortality after coronary-artery bypass grafting (CABG) than after percutaneous coronary intervention (PCI) among patients with multivessel disease. These previous analyses did not evaluate PCI with second-generation drug-eluting stents. METHODS: In an observational registry study, we compared the outcomes in patients with multivessel disease who underwent CABG with the outcomes in those who underwent PCI with the use of everolimus-eluting stents. The primary outcome was all-cause mortality. Secondary outcomes were the rates of myocardial infarction, stroke, and repeat revascularization. Propensity-score matching was used to assemble a cohort of patients with similar baseline characteristics. RESULTS: Among 34,819 eligible patients, 9223 patients who underwent PCI with everolimus-eluting stents and 9223 who underwent CABG had similar propensity scores and were included in the analyses. At a mean follow-up of 2.9 years, PCI with everolimus-eluting stents, as compared with CABG, was associated with a similar risk of death (3.1% per year and 2.9% per year, respectively; hazard ratio, 1.04; 95% confidence interval [CI], 0.93 to 1.17; P = 0.50), higher risks of myocardial infarction (1.9% per year vs. 1.1% per year; hazard ratio, 1.51; 95% CI, 1.29 to 1.77; P<0.001) and repeat revascularization (7.2% per year vs. 3.1% per year; hazard ratio, 2.35; 95% CI, 2.14 to 2.58; P<0.001), and a lower risk of stroke (0.7% per year vs. 1.0% per year; hazard ratio, 0.62; 95% CI, 0.50 to 0.76; P<0.001). The higher risk of myocardial infarction with PCI than with CABG was not significant among patients with complete revascularization but was significant among those with incomplete revascularization (P = 0.02 for interaction). CONCLUSIONS: In a contemporary clinical-practice registry study, the risk of death associated with PCI with everolimus-eluting stents was similar to that associated with CABG. PCI was associated with a higher risk of myocardial infarction (among patients with incomplete revascularization) and repeat revascularization but a lower risk of stroke. (Funded by Abbott Vascular.)published_or_final_versio

Efficacy of cilostazol on platelet reactivity and cardiovascular outcomes in patients undergoing percutaneous coronary intervention: insights from a meta-analysis of randomised trials

Background: Cilostazol overcomes high on-treatment platelet reactivity (HTPR) and reduces adverse cardiovascular (CV) outcomes after percutaneous coronary intervention (PCI). However, the role for triple antiplatelet therapy (TAPT) with cilostazol in addition to aspirin and clopidogrel after PCI is not well defined. Methods: We conducted a MEDLINE/EMBASE/CENTRAL search for randomised trials, until May 2014, evaluating TAPT compared with dual antiplatelet therapy (DAPT) of aspirin and clopidogrel alone in patients undergoing PCI and reporting platelet reactivity and/or CV outcomes. The primary platelet reactivity outcome was differences in platelet reactivity unit (PRU) with secondary outcomes of %platelet inhibition and rate of HTPR. The primary CV outcome was major adverse cardiovascular events (MACE), with secondary outcomes of death, cardiovascular death, myocardial infarction, stent thrombosis (ST), target lesion revascularisation (TLR) and target vessel revascularisation (TVR) as well as safety outcomes of bleeding and drug discontinuations. Results: In 17 trials that evaluated platelet reactivity outcomes, the mean PRU value was 47.73 units lower with TAPT versus DAPT (95% CI −61.41 to −34.04, p<0.0001; mean PRU 182.90 vs 232.65). TAPT also increased platelet inhibition by 12.71% (95% CI 10.76 to 14.67, p<0.0001), and led to a 60% reduction in the risk of HTPR (relative risk=0.40; 95% CI 0.30 to 0.53) compared with DAPT. Moreover, among the 34 trials that evaluated CV outcomes, TAPT reduced the risk of MACE (incident rate ratio (IRR)=0.68; 95% CI 0.60 to 0.78), TLR (IRR=0.57; 95% CI 0.44 to 0.73), TVR (IRR=0.69; 95% CI 0.59 to 0.81) and ST (IRR=0.63; 95% CI 0.40 to 0.98) with no difference for other outcomes including bleeding, even in trials using drug-eluting stents. Drug discontinuation due to adverse effects was, however, higher with TAPT vs DAPT (IRR=1.59; 95% CI 1.32 to 1.91). Conclusions: In patients undergoing PCI, addition of cilostazol to DAPT results in decreased platelet reactivity and a significant reduction in CV outcomes including ST, even in the drug-eluting stent era

Endothelial progenitor cell biology in disease and tissue regeneration

Endothelial progenitor cells are increasingly being studied in various diseases ranging from ischemia, diabetic retinopathy, and in cancer. The discovery that these cells can be mobilized from their bone marrow niche to sites of inflammation and tumor to induce neovasculogenesis has afforded a novel opportunity to understand the tissue microenvironment and specific cell-cell interactive pathways. This review provides a comprehensive up-to-date understanding of the physiological function and therapeutic utility of these cells. The emphasis is on the systemic factors that modulate their differentiation/mobilization and survival and presents the challenges of its potential therapeutic clinical utility as a diagnostic and prognostic reagent

Silicon based substrate with calcium aluminosilicate environmental/thermal barrier layer

A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a calcium alumino silicate

Silicon based substrate with calcium aluminosilicate/thermal barrier layer

A barrier layer for a silicon containing substrate which inhibits the formation of gaseous species of silicon when exposed to a high temperature aqueous environment comprises a calcium alumino silicate