20 resultados para Hexagonal boron nitride


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Prompt gamma activation analysis (PGAA) is especially sensitive for elements with high neutron-capture cross sections, like boron, which can be detected down to a level of ng/g. However, if it is a major component, the high count rate from its signal will distort the spectra, making the evaluation difficult. A lead attenuator was introduced in front of the HPGe-detector to reduce low-energy gamma radiation and specifically the boron gamma rays reaching the detector, whose thickness was found to be optimal at 10 mm. Detection efficiencies with and without the lead attenuator were compared, and it was shown that the dynamic range of the PGAA technique was significantly increased. The method was verified with the analyses of stoichiometric compounds: TiB2, NiB, PVC, Alborex, and Alborite.

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Aims: Stents with a passive coating of titanium-nitride-oxide (TiNO) have been compared with Endeavor® zotarolimus-eluting stents (E-ZES) with regard to the primary endpoint of in-stent late lumen loss at six to eight months. The objective of the present analysis was to compare the long-term outcomes of TiNO stents with E-ZES up to five years of clinical follow-up. Methods and results: A total of 302 patients had been randomly allocated to treatment with TiNO or E-ZES. Up to five years of follow-up, major adverse cardiac events (MACE), the composite of cardiac death, myocardial infarction, or clinically indicated target vessel revascularisation (TLR), were observed in 27.6% of patients treated with TiNO stents and 25.3% of patients treated with E-ZES (RR 1.13, 95% CI: 0.72-1.75, p=0.60), with the majority of events related to clinically indicated TVR (TiNO 21.7% versus E-ZES 20.7%, RR 1.10, 95% CI: 0.67-1.81). There were no differences with respect to individual events including cardiac death, myocardial infarction or stent thrombosis between the two treatment arms up to five years of follow-up. A majority of patients remained free from angina throughout the entire study duration (TiNO 77.3% versus E-ZES 76.1%, p=0.92). Conclusions: Final five-year outcomes of the TIDE trial comparing TiNO stents with E-ZES revealed increased rates of MACE driven primarily by clinically indicated TVR. The TIDE trial is registered at ClinicalTrials.gov: NCT00492908.