Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

Investigation of Ta-MX/Z-Phase and Laves Phase as Precipitation Hardening Particles in a 12 Pct Cr Heat-Resistant Steel

A 12%Cr martensitic/ferritic steel was designed and produced to study Laves and Z-phase as precipitation hardening particles under creep conditions at 650ºC. To ensure the precipitation of Laves after tempering, additions of W and Cu were selected according to thermodynamic calculations. It is known that Z-phase formation does not follows the classical nucleation theory. Indeed, MX particles are transformed into Z-phase by Cr diffusion from the matrix to the precipitate. Therefore, to promote fast Z-phase formation, Ta, Co and N additions were used to produce Ta-MX which will be transformed into Z-phase. As main results, Laves precipitation was successfully achieved after tempering with a particle size of 196nm. Concerning Z-phase, the transformation of Ta-MX into Z-phase after tempering was confirmed by the formation of hybrid nanoparticles of 30nm. Although, W and Ta have a low diffusion in martensitic/ferritic matrix, characterization of the precipitates after isothermal aging revealed that Laves and Z-phase have a fast growth kinetic, reaching 400nm and 143nm respectively at 8760h. As consequence, creep test at 650ºC showed prematurely fails after few thousand hours. Therefore, investigations focused on the growth and coarsening behavior of Laves and Z-phase, seem to be the next researcher field of martensitic/ferritic steels

Thermomechanical modeling and experimental study of a multi-layer cast iron repair welding for weld-induced crack prediction

Large-scale components such as hubs in wind turbines are often made of cast iron to minimize the production costs. One of the common challenges in the casting process of such large-scale components is manufacturing defects. However, repair welding will induce residual stress which can initiate cracks in the repaired structure, especially since cast iron is not as tough as steel. The current study addresses developing a thermo-mechanical model of the cast iron repair weld validated with experiments to predict thermal and residual stresses and to identify critical locations for crack initiation. A thermo-mechanical weld model is developed, and the predicted temperature and residual stress distribution are validated against experimental data. Two repair weld experiments, one manual and one automated are carried out and are simulated using the developed thermo-mechanical model. The regions with maximum principal residual stresses are calculated by the thermo-mechanical model and the maximum principal stress method is used to predict the location and direction of the developed cracks in the repair weld. A comparison with the repair weld experiments shows good correlation with the observed cracks in the welded specimens. The outcome of this research provides a basis for repair weld optimization of large-scale cast iron components in order to reduce the carbon footprint caused by their reproduction

New White Etch Cracking resistant martensitic stainless steel for bearing applications by high temperature solution nitriding

White Etch Cracking (WEC) is a severe and unpredictable failure mode that has been frequently observed in, among others, bearings for wind energy applications. In this work a novel, patented, WEC resistant bearing steel solution is developed through high temperature solution nitriding, followed by a custom heat treatment. Conventional medium carbon, 13 wt% Cr martensitic stainless steels were subjected to the novel process to obtain a nitrogen-rich case. A series of soft annealing, austenitization, cryogenic and tempering treatments converted the nitrogen-rich region into a fine-grained case containing nano-sized precipitates. Test bearings and tribometer specimens were treated with the same sequence of treatments. These specimens were tested under two different accelerated WEC failure promoting conditions. In contrast to standard through-hardened bearing steel the nitrided specimens showed no WEC formation, not even after prolonged testing