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William D. Leslie - One of the best experts on this subject based on the ideXlab platform.

  • CRAX: A simple cardiovascular risk assessment tool to predict risk of acute myocardial infarction or death
    Journal of Nuclear Cardiology, 2018
    Co-Authors: Patrick Martineau, Piotr Slomka, Andrew Goertzen, William D. Leslie
    Abstract:

    Background Determining the risk of cardiovascular events is essential to optimize patient management. Methods and Results 5842 individuals underwent SPECT myocardial perfusion imaging (MPI) with 4.4 ± 1.2 years of follow-up. Models (the CRAX tool) were derived to predict the cumulative risk of death and acute myocardial infarction (AMI) at 1, 3, and 5 years using clinical and MPI variables. Predictors of AMI and death included age, number of hospitalizations in the 3 years preceding MPI, and left ventricular ejection fraction (LVEF). Additional predictors of death were the use of pharmacological Stress, and Global Stress total perfusion deficit (sTPD), while transient ischemic dilation (TID), and ischemic total perfusion deficit (iTPD) change were predictive of AMI. CRAX predictions were significantly ( P  

  • CRAX: A simple cardiovascular risk assessment tool to predict risk of acute myocardial infarction or death
    Journal of Nuclear Cardiology, 2018
    Co-Authors: Patrick Martineau, Piotr Slomka, Andrew Goertzen, William D. Leslie
    Abstract:

    Background Determining the risk of cardiovascular events is essential to optimize patient management. Methods and Results 5842 individuals underwent SPECT myocardial perfusion imaging (MPI) with 4.4 ± 1.2 years of follow-up. Models (the CRAX tool) were derived to predict the cumulative risk of death and acute myocardial infarction (AMI) at 1, 3, and 5 years using clinical and MPI variables. Predictors of AMI and death included age, number of hospitalizations in the 3 years preceding MPI, and left ventricular ejection fraction (LVEF). Additional predictors of death were the use of pharmacological Stress, and Global Stress total perfusion deficit (sTPD), while transient ischemic dilation (TID), and ischemic total perfusion deficit (iTPD) change were predictive of AMI. CRAX predictions were significantly ( P  

Dungan Wang - One of the best experts on this subject based on the ideXlab platform.

  • a computational study of local Stress intensity factor solutions for kinked cracks near spot welds in lap shear specimens
    International Journal of Solids and Structures, 2005
    Co-Authors: Dungan Wang
    Abstract:

    In this paper, the local Stress intensity factor solutions for kinked cracks near spot welds in lap-shear specimens are investigated by finite element analyses. Based on the experimental observations of kinked crack growth mechanisms in lap-shear specimens under cyclic loading conditions, three-dimensional and two-dimensional plane-strain finite element models are established to investigate the local Stress intensity factor solutions for kinked cracks emanating from the main crack. Semi-elliptical cracks with various kink depths are assumed in the three-dimensional finite element analysis. The local Stress intensity factor solutions at the critical locations or at the maximum depths of the kinked cracks are obtained. The computational local Stress intensity factor solutions at the critical locations of the kinked cracks of finite depths are expressed in terms of those for vanishing kink depth based on the Global Stress intensity factor solutions and the analytical kinked crack solutions for vanishing kink depth. The three-dimensional finite element computational results show that the critical local mode I Stress intensity factor solution increases and then decreases as the kink depth increases. When the kink depth approaches to 0, the critical local mode I Stress intensity factor solution appears to approach to that for vanishing kink depth based on the Global Stress intensity factor solutions and the analytical kinked crack solutions for vanishing kink depth. The two-dimensional plane-strain computational results indicate that the critical local mode I Stress intensity factor solution increases monotonically and increases substantially more than that based on the three-dimensional computational results as the kink depth increases. The local Stress intensity factor solutions of the kinked cracks of finite depths are also presented in terms of those for vanishing kink depth based on the Global Stress intensity factor solutions and the analytical kinked crack solutions for vanishing kink depth. Finally, the implications of the local Stress intensity factor solutions for kinked cracks on fatigue life prediction are discussed.

  • Stress intensity factors for spot welds and associated kinked cracks in cup specimens
    International Journal of Fatigue, 2005
    Co-Authors: Dungan Wang, S.-h. Lin, J. Pan
    Abstract:

    In this paper, the Stress intensity factors for spot welds in cylindrical-cup and square-cup specimens are investigated by finite element analyses. Axisymmetric and three-dimensional finite element models are developed for circular plates and cylindrical-cup specimens to establish the finite element meshes needed to obtain accurate Global Stress intensity factor solutions. The Global Stress intensity factors are compared with the existing analytical solutions for circular plates. Then a three-dimensional finite element model based on the finite element mesh for cylindrical-cup specimens is established to obtain the Global Stress intensity factors for square-cup specimens. Based on the computational results, a closed-form Stress intensity factor solution is suggested for square-cup specimens. Next, based on the experimental observations of kinked crack growth mechanisms in square-cup specimens under cyclic loading conditions, axisymmetric finite element models are established to investigate the local Stress intensity factor solutions for kinked cracks emanating from the main crack. Both circular and rectangular shaped notch tip and a sharp crack tip are considered for the main crack. Various kink lengths are considered. The local Stress intensity factor solutions for kinked cracks are obtained. The results show that the local Stress intensity factors for kinked cracks with finite kink lengths are much higher than those based on the closed-form solutions for kinked cracks with vanishing kink length. Finally, the implications of the local Stress intensity factor solutions for kinked cracks on fatigue life prediction are discussed.

J. Pan - One of the best experts on this subject based on the ideXlab platform.

  • Stress intensity factors for spot welds and associated kinked cracks in cup specimens
    International Journal of Fatigue, 2005
    Co-Authors: Dungan Wang, S.-h. Lin, J. Pan
    Abstract:

    In this paper, the Stress intensity factors for spot welds in cylindrical-cup and square-cup specimens are investigated by finite element analyses. Axisymmetric and three-dimensional finite element models are developed for circular plates and cylindrical-cup specimens to establish the finite element meshes needed to obtain accurate Global Stress intensity factor solutions. The Global Stress intensity factors are compared with the existing analytical solutions for circular plates. Then a three-dimensional finite element model based on the finite element mesh for cylindrical-cup specimens is established to obtain the Global Stress intensity factors for square-cup specimens. Based on the computational results, a closed-form Stress intensity factor solution is suggested for square-cup specimens. Next, based on the experimental observations of kinked crack growth mechanisms in square-cup specimens under cyclic loading conditions, axisymmetric finite element models are established to investigate the local Stress intensity factor solutions for kinked cracks emanating from the main crack. Both circular and rectangular shaped notch tip and a sharp crack tip are considered for the main crack. Various kink lengths are considered. The local Stress intensity factor solutions for kinked cracks are obtained. The results show that the local Stress intensity factors for kinked cracks with finite kink lengths are much higher than those based on the closed-form solutions for kinked cracks with vanishing kink length. Finally, the implications of the local Stress intensity factor solutions for kinked cracks on fatigue life prediction are discussed.

  • Fatigue life prediction for spot welds in coach-peel and lap-shear specimens with consideration of kinked crack behaviour
    International Journal of Materials & Product Technology, 2004
    Co-Authors: S.-h. Lin, J. Pan
    Abstract:

    A fracture mechanics approach is adopted to examine the fatigue lives of spot welds in coach-peel and lap-shear specimens with consideration of kinked crack behaviour. The paths of fatigue cracks near the spot welds in these two types of specimens are first discussed. A fatigue crack growth model is then developed for spot welds in these two types of specimens based on the local Stress intensity factor solutions for kinked cracks and the Paris law for crack propagation. Various Global Stress intensity factor solutions for spot welds in these two types of specimens are used to obtain the local Stress intensity factor solutions with the experimentally determined kink angles. The results indicate that the fatigue life predictions based on accurate Global Stress intensity factor solutions can characterise the general trend of the experimental results. The effects of the kink angle on the fatigue life predictions are also discussed.

Patrick Martineau - One of the best experts on this subject based on the ideXlab platform.

  • CRAX: A simple cardiovascular risk assessment tool to predict risk of acute myocardial infarction or death
    Journal of Nuclear Cardiology, 2018
    Co-Authors: Patrick Martineau, Piotr Slomka, Andrew Goertzen, William D. Leslie
    Abstract:

    Background Determining the risk of cardiovascular events is essential to optimize patient management. Methods and Results 5842 individuals underwent SPECT myocardial perfusion imaging (MPI) with 4.4 ± 1.2 years of follow-up. Models (the CRAX tool) were derived to predict the cumulative risk of death and acute myocardial infarction (AMI) at 1, 3, and 5 years using clinical and MPI variables. Predictors of AMI and death included age, number of hospitalizations in the 3 years preceding MPI, and left ventricular ejection fraction (LVEF). Additional predictors of death were the use of pharmacological Stress, and Global Stress total perfusion deficit (sTPD), while transient ischemic dilation (TID), and ischemic total perfusion deficit (iTPD) change were predictive of AMI. CRAX predictions were significantly ( P  

  • CRAX: A simple cardiovascular risk assessment tool to predict risk of acute myocardial infarction or death
    Journal of Nuclear Cardiology, 2018
    Co-Authors: Patrick Martineau, Piotr Slomka, Andrew Goertzen, William D. Leslie
    Abstract:

    Background Determining the risk of cardiovascular events is essential to optimize patient management. Methods and Results 5842 individuals underwent SPECT myocardial perfusion imaging (MPI) with 4.4 ± 1.2 years of follow-up. Models (the CRAX tool) were derived to predict the cumulative risk of death and acute myocardial infarction (AMI) at 1, 3, and 5 years using clinical and MPI variables. Predictors of AMI and death included age, number of hospitalizations in the 3 years preceding MPI, and left ventricular ejection fraction (LVEF). Additional predictors of death were the use of pharmacological Stress, and Global Stress total perfusion deficit (sTPD), while transient ischemic dilation (TID), and ischemic total perfusion deficit (iTPD) change were predictive of AMI. CRAX predictions were significantly ( P  

Piotr Slomka - One of the best experts on this subject based on the ideXlab platform.

  • CRAX: A simple cardiovascular risk assessment tool to predict risk of acute myocardial infarction or death
    Journal of Nuclear Cardiology, 2018
    Co-Authors: Patrick Martineau, Piotr Slomka, Andrew Goertzen, William D. Leslie
    Abstract:

    Background Determining the risk of cardiovascular events is essential to optimize patient management. Methods and Results 5842 individuals underwent SPECT myocardial perfusion imaging (MPI) with 4.4 ± 1.2 years of follow-up. Models (the CRAX tool) were derived to predict the cumulative risk of death and acute myocardial infarction (AMI) at 1, 3, and 5 years using clinical and MPI variables. Predictors of AMI and death included age, number of hospitalizations in the 3 years preceding MPI, and left ventricular ejection fraction (LVEF). Additional predictors of death were the use of pharmacological Stress, and Global Stress total perfusion deficit (sTPD), while transient ischemic dilation (TID), and ischemic total perfusion deficit (iTPD) change were predictive of AMI. CRAX predictions were significantly ( P  

  • CRAX: A simple cardiovascular risk assessment tool to predict risk of acute myocardial infarction or death
    Journal of Nuclear Cardiology, 2018
    Co-Authors: Patrick Martineau, Piotr Slomka, Andrew Goertzen, William D. Leslie
    Abstract:

    Background Determining the risk of cardiovascular events is essential to optimize patient management. Methods and Results 5842 individuals underwent SPECT myocardial perfusion imaging (MPI) with 4.4 ± 1.2 years of follow-up. Models (the CRAX tool) were derived to predict the cumulative risk of death and acute myocardial infarction (AMI) at 1, 3, and 5 years using clinical and MPI variables. Predictors of AMI and death included age, number of hospitalizations in the 3 years preceding MPI, and left ventricular ejection fraction (LVEF). Additional predictors of death were the use of pharmacological Stress, and Global Stress total perfusion deficit (sTPD), while transient ischemic dilation (TID), and ischemic total perfusion deficit (iTPD) change were predictive of AMI. CRAX predictions were significantly ( P