In emergency department acute, low-risk chest pain patients, the use of CCTA results in more rapid and cost-efficient safe diagnosis than rest-stress MPI. Further studies comparing CCTA to other diagnostic strategies are needed to optimize evaluation of specific patient subsets. (Coronary Computed Tomographic Angiography for Systematic Triage of Acute Chest Pain Patients to Treatment [CT-STAT]; NCT00468325).

Prior epidemiologic studies have shown that increasing body mass index (BMI) is associated with higher total cholesterol and low-density lipoprotein cholesterol (LDL). However, these studies were limited by underrepresentation of obese subjects. The aim of this study was to determine whether there is an association between BMI and lipid profiles in a population of patients with a broad spectrum of BMI values. A case-control study was performed involving patients seen at the Cleveland Clinic Florida. Cases (BMI >30 kg/m(2)) were obtained from the obesity surgery database between August 31, 2000, and April 4, 2002. Controls (BMI ≤ 30 kg/m(2)) were obtained from a database of primary care physicians between May 1, 2004, and November 18, 2004. Pearson correlation coefficients were used to assess the relationship between BMI and lipid fractions. Multiple linear regression was performed to assess the independent effect of BMI on lipid levels while adjusting for potential confounders and propensity scores. Six hundred thirty-seven patients were analyzed (females, n = 362, 57%). There was no association between higher BMI and LDL (r = 0.19 p = 0.07), a negative association with high-density lipoprotein cholesterol (HDL; r = 0.45, p < 0.001), and a positive association with the log transformation of triglycerides (r = 0.32, p = 0.005).Higher BMI was inversely associated with HDL and directly associated with TG. BMI showed no significant association with LDL. Although the association between BMI and both HDL and TG may be explained by insulin resistance, the lack of a significant association between BMI and LDL remains an unexpected finding that requires further investigation.

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The equation of motion and associated boundary conditions are derived for a uniform Bernoulli-Euler beam containing one single-edge crack. The main idea is to use a generalized variational principle that allows for modified stress, strain, and displacement fields that enable one to satisfy the compatibility requirements in the vicinity of the crack. The concentration in stress is represented by introducing a crack function into the beam's compatibility relations. A displacement function is also introduced to modify the in-plane displacement and its slope near the crack. Both functions are chosen to have their maximum value at the' cracked section and to decay exponentially along the beam's longitudinal direction. The rate of exponential decay is evaluated from finite element calculations. The resulting equation of motion is solved for simply supported and cantilevered beams with single-edge cracks by a Gderkin and a local Ritz procedure, respectively. These theoretical natural frequencies and mode shapes are confirmed by comparisons with experimental and finite element results, and in both cases a close match is obtained. The possibility of determining the cracked beams' damage properties from the changes of its dynamic behavior is discussed.

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An energy based fatigue life prediction framework has been developed for calculation of remaining fatigue life of in service gas turbine materials. The purpose of the life prediction framework is to account aging effect caused by cyclic loadings on fatigue strength of gas turbine engines structural components which are usually designed for very long life. Previous studies indicate the total strain energy dissipated during a monotonic fracture process and a cyclic process is a material property that can be determined by measuring the area underneath the monotonic true stress-strain curve and the sum of the area within each hysteresis loop in the cyclic process, respectively. The energy-based fatigue life prediction framework consists of the following entities: (1) development of a testing procedure to achieve plastic energy dissipation per life cycle and (2) incorporation of an energy-based fatigue life calculation scheme to determine the remaining fatigue life of in-service gas turbine materials. The accuracy of the remaining fatigue life prediction method was verified by comparison between model approximation and experimental results of Aluminum 6061-T6. The comparison shows promising agreement, thus validating the capability of the framework to produce accurate fatigue life prediction.

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